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Book * r ~' 

fiop\Tighf N ° . 


COFflRIGOT DEPOSIT. 












































.. 














. 











































. 























Diagnosis and 
Treatment 

of 

Internal Parasites 

. 

bi| II1AUR1CE C HALL 

PH. D„ D. V. m. 

Senior Zoologist of the United States Depart¬ 
ment of Agriculture, Editor, Department of 
Parasitology of Ueterinary Tlledicine. 

2nD REUISED EDITIOU 


This is the first of a series of books on Para¬ 
sitology of domestic animals by Dr. ITlaurice 
C. Hall to be published by Ueterinary Medicine. 
<The entire series mill contain about 3000 pages. 


PUBLISHED Blf 

UETERIHARIJ IT1EDICINE 

1827 S. IDabash Auenue, Chicago, III. 
1023 













SFe*q 

Preface\vSf 


This small volume is the first of a series of books on par¬ 
asitology of domestic animals by Maurice C. Hall to be pub¬ 
lished by VETERINARY MEDICINE. Other volumes cov¬ 
ering the whole subject thoroughly and comprehensively will 
follow in regular order. The entire set, like the present one, 
will be profusely illustrated and when complete will cover 
approximately 3,000 pages. 

This stupendous enterprise is undertaken with no other 
object than that of supplying a crying, current need to the 
veterinary profession. In short, we have thought it little less 
than a crime to leave Dr. Hall’s investigations and exceedingly 
practical information unpublished any longer, because the toll 
parasites are taking from the livestock interests, already enor¬ 
mous, is destined to become greater and greater as the popu¬ 
lation and the mean value of animals increase. 

Impelled and inspired by the outstanding fact that the 
author is a capable writer, a world authority, and a highly 
practical therapist on the subject of parasitology, this initial 
contribution is submitted to the scrutiny of the critic. 

THE PUBLISHERS OF 
VETERINARY MEDICINE 


Copyright, 1923, by 
L. A. MERILLAT 



\G 1923 

C1A766285 


CONTENTS 


LABORATORY DIAGNOSIS AND 
ASITIC INFESTATION 


TREATMENT OF INTERNAL PAR- 


Collecting and Examining Parasites—Handling Specimens Collected—Exam¬ 
ination of Stomach Contents—Examination of the Lungs—Excretory System, 
Circulatory System, Muscular System, Skeleton and Nervous System—Exam¬ 
ination of Specimens. 


5-11 


EXAMINING FECES FOR PARASITES AND PARASITIE EGGS 

Technic of Fecal Examinations—Screening—Examination for Eggs—A Sim- 
pie Technic Standard Methods Apply Only to Human Feces.12—16 


EGGS AND LARVAE OF DOG, CAT AND FOX PARASITES 
Twenty-four Illustrations . 


17-25 


EGGS AND LARVAE OF SWINE PARASITES 

Thirteen Illustrations . 26—32 

EGGS AND LARVAE OF CATTLE, SHEEP AND GOAT PARASITES 

Nineteen Illustrations .33—42 


EGGS AND LARVAE OF HORSE PARASITES 

Twenty-two Illustrations .43-48 

EGGS AND LARVAE OF POULTRY PARASITES 

Twenty-six Illustrations .49-58 


SPURIOUS PARASITES IN THE FECES OF ANIMALS 

Sixteen Illustrations .59-66 

ANTHELMINTIC MEDICATION FOR WORMS OUTSIDE THE DIGES- 
TIV E TRACT. Liver Fluke Medication—Blood Flukes in Man-Value of 
Medication—Cestode Medication—Nematode Medication—Treatment of Trich¬ 
inosis—Treatment of Filarids.... 67-74 


ANTHELMINTIC MEDICATION FOR WORMS IN THE LUMEN OF 
THE DIGESTIVE TRACT. Fasting—Mass Treatment versus Individual 
Treatment—Complications Due to Larval Worms—Periods during which 
Worms are Passed—Examination of Feces for Worms Passed.75-78 


TREATMENT OF HORSE PARASITES. Ascarids, Palisade Worms, Cyli- 

costomes, Pinworms, Stomach Worms, Tapeworms.78-80 

TREATMENT OF CATTLE PARASITES. Ascarids, Stomach Worms, Hook¬ 
worms, Nodular Worms, Small Trichostrongyles, Tapeworms.80-81 

TREATMENT OF SHEEP AND GOAT PARASITES. Stomach Worms, 
Hookworms, Nodular Worms, Nematodirus, Cooperia, Ostertagia, Tricho¬ 
strongyles, Tapeworms ...82-84 


TREATMENT OF SWINE PARASITES. Ascarids, Stomach Worms, Nodular 


Worms, Thorny-headed Worms, Tapeworms.84-86 

TREATMENT OF DOG PARASITES. Ascarids, Hookworms, Whipworms, 

Tapeworms .87-90 

TREATMENT OF CAT PARASITES. Ascarids, Hookworms, Tapeworms.90 

TREATMENT OF FOX PARASITES. Ascarids, Tapeworms, Whipworms, 

Tapeworms, Flukes .90—91 

TREATMENT OF POULTRY PARASITES. Large Roundworms, Cecum 

Worm, Spirurids, Tapeworms.91-92 


METHODS AND TECHNIC OF ADMINISTERING ANTHELMINTICS..93-102 


3 





















Copyright, 1923, by 


L. A. MERILLAT 



The Laboratory Diagnosis and the 
Treatment of Internal Parasitic 
Infestation 

Collecting and Examining Parasites 

The collection of parasites calls for certain personal equipment 
and a limited amount of apparatus. Some collectors have a highly 
developed personal equipment. It consists in: 1, an intense and 
persistent interest in parasites; 2, a tremendous curiosity on the sub¬ 
ject, which leads one to scrutinize every suspicious object as a pos¬ 
sible parasite; 3, an equal amount of pertinacity, which impels the 
investigation of these objects until they are definitely proven para¬ 
sitic or non-parasitic and not merely probably one thing or an¬ 
other; 4, a faith and conviction that there are parasites present; 
5, a thoroughness which lets no parasite escape. To collect para¬ 
sites one should be in the mood to collect parasites. Given this, one 
needs only keen eyesight, a small amount of apparatus and a system 
for examination of the host animal. 

Search Everywhere 

As regards a system for examining animals for parasites, one 
must know where to look. So far as time and other circumstances 
permit, look everywhere. Examine all pathological conditions as 
possibly of parasitic nature. Examine all cavities, large and small. 
Assume that the digestive tract always has parasites; that the respi- 
tory and circulatory systems sometimes harbor parasites, and that 
the skeletal, muscular, nervous and reproductive systems may harbor 
parasites at times. 

Superficial Examination Not Sufficient. 

In examining an animal for parasites, the usual postmortem ex¬ 
amination instruments, knives, scalpels, forceps, etc., are necessary. 
In addition an enterotome is essential; it is the one instrument which 
the parasitologist finds indispensable. The intestine is such an im¬ 
portant site of infestation for parasites that the enterotome with 


5 


the guarded point saves a large aggregate amount of time over ordi¬ 
nary scissors or a knife in opening intestines. Too many routine 
postmortem examinations fail to take into consideration the lumen 
and inner lining of the stomach and intestines. The condition of the 
mucosa and the presence or absence of parasites are guessed at from 
a superficial observation of the serous coat. This method affords 
inferior evidence as to conditions present and the parasitologist can¬ 
not use such a method in examining animals for parasites. It is true 
that ascarids and other worms may at times be detected in this man¬ 
ner, but it is also true that large numbers of worms cannot be de¬ 
tected in this manner. For all-around use, an enterotome should 
have long, comparatively narrow blades with a guard of moderate size 
on one blade. Such an enterotome can be used on anything from 
the size of a chicken to that of a horse. 

Handling Specimens Collected 

A few tall jars, some glass dishes and an ample supply of running 
water are a great aid in collecting certain kinds of parasites. Rubber 
gloves may be used if desired; they afford protection from infection 
and also from undesirable odors on the hands. In the postmortem 
examination of the dog, cat, swine or animals of similar siz-e, it is 
advisable to put the stomach into one jar of water, or, better, physio¬ 
logic saline solution, the small intestine into another jar, the cecum 
into another and the colon and rectum into another. Slit each of 
these organs, wash the contents into the jar, scraping off adherent ma¬ 
terial from the organ, especially its mucosa, and then discard it. 
After the contents of the jar have sedimented, decant the supernatant 
fluid down to the mass of intestinal contents at the bottom of the jar, 
getting rid of the soluble coloring matter and the floating flocculent 
matter. Worms will remain in the heavier ingesta at the bottom. 
Add fresh water or saline and again decant, repeating this process until 
the supernatant fluid over the intestinal contents is clear. It is ad¬ 
visable to let the fresh water trickle down the sides of the jar in order 
not to form bubbles which may carry parasites to the surface. In 
fact all matter flowing out of the jar in the process of decanting should 
be scrutinized for possible parasites sustained by air bubbles, straw, etc. 

When the supernatant fluid is clear, the material in the jar should 
be agitated in order to stir up the intestinal contents and a small amount 


6 


of this material should be poured into a glass dish and examined over 
a dark background, the dish itself being in a good light. The best 
background is that afforded by a shadowy floor when the dish is 
held at the level of the laboratory table. Parasites are visible as dis¬ 
tinct objects of definite outline, frequently white or yellowish, though 
sometimes red or motley colored, and usually actively motile. They 
may be picked out with a dissecting needle, forceps, or, if very small, 
with a pipette. Where such objects appear, but are not definitely 
recognizable, the use of a small hand lens, with a magnification of 6 
to 12 diameters, will usually aid in determining their nature. Failing 
this, one must resort to the use of the dissecting microscope, binocular 
or ordinary compound microscope. 

Examination of Stomach Contents of Large Animals 

With such large animals as horses, cattle and sheep, it is seldom 
necessary or feasible to wash and decant the stomach contents. The 
stomach of the horse may be slit and the gastric .mucosa carefully 
examined after the contents have been rolled out in such a way as to 
keep them together as much as possible. An examination of the ex¬ 
terior of this mass of contents, the part which has been in contact with 
the stomach wall, will usually show many more parasites than the 
interior of the mass, or the part which occupied the central portion 
of the gastric lumen. The rumen, reticulum and omasum may be 
slit and examined in a similar manner in the case of ruminants, but 
the fourth stomach or abomasum should be washed and decanted. 
Parasites are occasionally present in the first three stomachs. They 
are almost always present in the fourth stomach. 

The Intestines of a Horse Rarely Washed 

The small intestine of the horse is rarely washed and examined 
fcr parasites and the large intestine cannot be satisfactorily handled 
in this manner. In the latter, the examination of the intestinal wall 
and of the contents in contact with the wall indicate well the nature 
of the parasites present, and where it is desired to obtain all the 
parasites present, so far as possible, as is the case in testing anthel- 


7 


mintics, the contents may be rolled into balls, squeezed to remove tht 
excess water, and carefully picked apart by hand. 

It is, of course, unnecessary to wash and decant in the case of 
the esophagus, since this organ is devoid of a constant content. The 
esophagus may be examined by stretching it between the hands and 
holding it up to the light in order to detect such worms as the gullet 
worms, the latter occurring in horses, cattle, sheep and swine. They 
may be detected under the mucosa of the tongue and pharynx, also, 
in some cases. 

Examination of the Lungs. 

The examination of the lungs for parasites may call for the 
use of both the enterotome and the knife. Cysts, such as those of the 
lung fluke, Paragonimus, may be sought for and investigated with 
the aid of the knife, but the nematodes known as lungworms, much 
commoner parasites, are best sought for with the aid of an enterotome. 
The entertome facilitates slitting the trachea, bronchi and smaller air 
tubes and these should be slit as far as possible, especially where 
the pulmonary pleura shows any evidence of inflamation, as the worms 
are frequently present only in the smaller tubes when present in 
small numbers. 

Occasionally even the trained pathologist will neglect the open¬ 
ing of the smaller air tubes and will search in vain for evidence of 
tuberculosis or other bacterial disease to account for symptoms and 
lesions due to worms which only need to be loked for to be found. 
Some of the smallest lungworms, such as some species from sheep, are 
difficult to detect and it may facilitate the search for these to put 
portions of the lung showing inflammation into water and look closed 
for worms floating out from the tissue. 

Sometimes microscopic examination of stained slides is neces¬ 
sary to demonstrate the small lungworms present. Numerous petechiae 
suggest the presence of larval ascarids or other worms; these petechial 
areas may be examined in press preparations under the microscope to 
determine the presence or absence of these worms. 

The use of two metal frames, connected by screws for pressing 
two heavy glass slides together, facilitates the examination of such 
specimens, but lacking such apparatus two ordinary glass slides may 
be utilized and held together by rubber bands if desired. All lesions 


8 


that could possibly be parasitic, and there is a wide range of such 
lesions, should be examined for parasites. 

Excretory System 

The excretory system may harbor such parasites as kidney worms 
in swine and the giant kidney worm in dogs. Larval worms may also 
occur in the kidneys, but these can only be detected or suspected on 
the evidence of lesions produced by them. 

Circulatory System 

In the circulatory system parasites may be expected in the an¬ 
terior mesenteric artery of horses in the large majority of cases 
(Strongylus vulgaris in verminous aneurisms) and in the right heart 
and pulmonary artery of many dogs in parts of the southern United 
States. A number of parasitic worms use the blood stream as a 
distributing current during part of their life history and the blood 
may be examined for such forms by laking with three percent glacial 
acetic acid and centrifuging, the sediment being examined micro¬ 
scopically for worms. 

Skeletal, Muscular and Nervous Systems 

Parasites in the skeletal, muscular, nervous and reproductive 
systems are not very common, but such parasites as hydatids in 
bones, trichinae in swine musculature, the gid bladderworm in the 
brain of sheep, and flukes and roundworms in the oviduct of chickens 
warrant us in remembering the possibility of such occurences and 
in investigating wherever symptoms or lesions suggest the ad¬ 
visability of so doing. 

Examination of the Specimen 

The parasites collected should be washed in physiologic saline 
solution to remove mucus and other adherent material, otherwise this 
material will interfere with proper fixation and frequently appear on 
mounted material at points where it obscures important anatomical 
details. After washing, nematodes should be transferred, whenever 
possible, to hot 70 percent alcohol, in which they usually straighten 
out in a satisfactory position for subsequent examination. Tape¬ 
worms and flukes are killed in a very satisfactory manner in equal 
parts of 70 percent alcohol and a saturated aqueous solution of cor¬ 
rosive sublimate, to which is added one percent glacial acetic acid. 
This may be used cold, or better, at a temperature of 70 to 80° C. 


9 


(158°-176° F.). Allow this mixture to act for 10 to 20 minutes. 
Subsequently these worms should be washed and then put in a tinc¬ 
ture of iodin to remove the excess of corrosive sublimate. For col¬ 
lecting specimens in the field or wherever there are no laboratory 
facilities, a weak formalin solution, one to two percent, is fairly 
satisfactory. 

Nematodes may be examined in physiologic saline while yet 
alive or cleared for study by transfer from 70 percent alcohol to the 
same strength of alcohol containing 5 to 10 percent glycerin. This 
mixture and the contained worms may then be placed in an incubator 
or paraffine oven and kept there until the evaporation of the alcohol 
leaves the specimens in glycerin. By this time the specimen is usually 
quite clear and the transfer to glycerin is sufficiently slow to prevent 
the distortion of the specimens by osmosis. The worms may then be 
permanently mounted in glycerin or glycerin jelly. Some nematodes, 
especially small ones, may be transferred to glycerin jelly directly 
from 70 percent alcohol without sufficient distortion to make an ordi¬ 
nary identification at all difficult, but large worms are usually much 
distorted by such a transfer. Another clearing agent consists of 20 
parts of absolute alcohol and 80 parts of carbolic acid. Nematodes 
are rarely stained for examination by most workers, as they are not 
amenable to most stains, but gentian violet is fairly penetrating and 
may be used to bring out many interesting details of structure. 
Haematoxylin is also used at times and gives a good picture. Oc¬ 
casionally nematodes are dehydrated, cleared and mounted in balsam, 
but this often makes them too transparent for some purposes and 
simpler and quicker methods are usually quite as satisfactory or more 
satisfactory. 

Tapeworms and flukes are usually stained, dehydrated, cleared 
and mounted in balsam for study and identification. Tapeworm scolices 
or heads may be mounted in glycerin, glycerin jelly or similar media 
for the examination of the hooks, and gravid segments are sometimes 
similarly mounted for the purpose of examining the eggs. 

Probably there is no field in which the veterinarian can find 
more new scientific facts with more ease than in the field of parasitol¬ 
ogy. A number of interesting parasites of the domesticated animals 


10 


were originally described from the United States and some of the 
records of rare parasites are from this country. 

Undoubtedly there are other undescribed parasites and unrecorded 
occurrences of rare parasites which would be brought to light if more 
veterinarians took an active interest in the subject of parasitology. 
It should be an especially interesting field to the young man who 
still has energy to expend on postmortem examinations and who has 
not yet grown rusty in regard to what he learned of parasitology in 
college. 


11 



Examining Feces for Parasites and 
Parasite Eggs 

T HE diagnosis of parasitic infestation of the stomach and in¬ 
testines, and to some extent infestation of the liver, respiratory 
tract and some other portions of the body, is largely based on 
miscroscopic, and to a lesser extent on macroscopic, examination of the 
feces. These diagnosis are, for the most part, quite positive and de¬ 
pendable and are not difficult to make. They call for the use of a 
microscope, a somewhat expensive piece of apparatus, but the present 
day veterinary practitioner who is using modern laboratory methods 
needs a microscope as an essential part of his equipment for a large 
amount of work other than diagnosing parasitic infestations. Aside 
from a microscope, slides and cover glasses, very little apparatus is 
necessary for examining feces for evidences of parasitism, though 
if one has much work of this sort to do, a slight increase in the amount 
of apparatus and a somewhat more elaborate technic will save time, 
nervous energy and eyestrain. 

Materials Sometimes Deceptive 

It is a common thing for the owners of livestock to find worms 
passed in the feces of their animals and to bring them to the veter¬ 
inarian for examination. Specimens of this sort are frequently easy 
to determine and a diagnosis of a definite sort follows immediately 
from the identification. Sometimes the specimens brought in for 
identification are spurious parasites, material of various sorts which 
is not parasitic, but which deceives the client and may at times de¬ 
ceive the veterinarian. A proper technic for the examination of feces 
where parasitism is suspected will usually save the veterinarian from 
error along this line. 

Technic of Fecal Examination 

It is intended here to outline for the most part only the principles 
underlying the technic used in examining feces. As a rule everyone 


12 


develops his own technic, this being largely a matter of personal 
preferences and local conditions. The same result can doubtless be 
obtained by any one of numerous variations in technic, and results 
are what count. 

Stirring With Stick May Fail 

The most simple and direct method of examining feces macro- 
scopically for evidence of parasitism consists in poking about in the 
manure with a stick or something of the sort for objects resembling 
worms. It is what the farmer usually does and what the veterinarian 
not uncommonly does. It must be admitted that occasionally one 
finds parasites in feces in this manner, but it must also be admitted that 
this is the least satisfactory method of examining feces. Parasites 
embedded in feces are easily overlooked and non-parasitic objects 
smeared with feces are easily mistaken for parasites. It is possible 
for horse manure to contain hundreds of worms and not one worm 
to be found by such technic. 

Technic Must Conform to Given Specimens 

To determine whether worms are present in feces, information 
which may be desired after the administration of an anthelmintic, 
one should adapt one’s technic to the nature of the feces. The 
physician has a comparatively simple task in examining human feces, 
since these feces are made up mostly of finely comminuted material 
and a very small amount of large coarse material. The veterinarian 
has no such simple task. Dog and cat feces are somewhat com¬ 
parable to human feces, but they contain more coarse material in 
many cases. Swine feces usually contain yet larger amounts of coarse 
material. Sheep and goat feces are commonly in hard pellets which 
must be broken up to permit of an examination of the comminuted 
vegetable material composing these pellets. Cow manure is usually 
soft enough to be easily examined, but its bulk is a disadvantage. 
Horse manure contains much coarse vegetable material and the 
manure for one day is bulky enough to require about a day’s work 
to examine it carefully and completely for worms. 


13 


Screening a Great Help 

Wherever it is feasible to screen feces to examine them for para¬ 
sites, screening is a great help. The feces of the dog, cat and pig 
may be broken up in water and screened without difficulty. Sheep 
and goat feces are much more difficult to handle in this way, though 
they can be screened to advantage in looking for parasites. Cow 
manure is easily screened, but its bulk makes the examination of the 
manure for one day a task. Horse manure is too coarse to screen 
successfully in the amounts passed in one day and must be examined 
by being carefully picked apart by hand. Wherever screens may 
be used, the nature of the screen to be used depends on circumstances. 

Where few fecal examinations are made and little apparatus 
is available, a piece of cheesecloth may be stretched over hoops or a 
bucket top to make a screen. Where fecal examinations are a routine 
matter, wire screens, such as copper or brass screens, of assorted 
sizes, from 6 to 100 mesh apertures to the inch, are of value. After 
the feces have been broken up thoroughly by soaking in water and 
shaking, they are poured through the screen or screens and each screen 
then put in a glass dish containing water and examined for para¬ 
sites. The material on the screen may be rinsed off into this glass 
dish and examined for worms or other parasites present. 

Examination for Parasite Eggs 

Where parasite eggs are sought for by microscopic examination, 
the simplest technic is the so-called smear method. A bit of feces 
is taken on a match, tooth-pick or stirring rod, rubbed to a uniform 
smear in a little water on a slide, covered with a cover glass and exam¬ 
ined under a microscope. It will afford satisfactory evidence as to 
the presence of parasite eggs provided there are numerous eggs 
present in the feces. For detecting gross infestations this method 
may be entirely satisfactory in some circumstances. It is not a 
delicate method and can not be depended on to detect light infestations. 
Its results become increasingly dependable in proportion to the num¬ 
ber of slides made and examined from a given fecal sample, but the 
length of time involved in examining such preparations makes it 


14 


far more profitable to put some of this time on the technical manipu¬ 
lation of the feces before making the slide to be examined, 

A Simple Technic 

The technical manipulation necessary to prepare more satisfac¬ 
tory slides for examining is designed to concentrate the parasite eggs 
originally scattered throughout the feces by removing that part of 
the feces which can readily be separated on the basis of differences 
in size, specific gravity, solubility, etc., in other words on the basis of 
physical and chemical differences. A simple technic that will give 
a high degree of concentration is as follows: Feces are broken up, 
screened through a set of screens placed in a rack with the coarse 
screens at the top and the finer ones at the bottom, the material 
passing through all the screens being caught in a suitable tray or dish; 
after standing a minute or so, the top half of this material is decanted 
and replaced by clean water; this process is repeated every minute 
until the soluble coloring matter and floating floeculent matter is 
poured away and the water stands clear on the sediment at the bot¬ 
tom; the water is then decanted until only a little is left on the 
sediment and this is shaken up and poured into a centrifuge tube 
till the tube is full; the tube is then set in a rack until ready to be 
examined. 

In the course of this manipulation, all fecal matter too coarse to 
pass through a screen of 100 apertures to the inch, which will allow the 
passage of the largest parasite eggs one need consider in work of this 
sort, has been eliminated by the screens; the soluble coloring matter 
and floating floeculent material which would obscure the view of the 
eggs on the slide have been eliminated by washing and sedimenting; 
what is left consists of parasite eggs and other material of approxi¬ 
mately the same size as the eggs or smaller, and material approxi¬ 
mately as heavy or heavier. 

When there is a bottom sediment evidently composed of sand in 
the tray or dish used to catch the feces passing through the screen, 
this should be allowed to stay in the dish and not rinsed into the 


15 


test tube as the eggs are lighter and will be on top of such sediment. 
The technic given in this discussion causes a high degree of con¬ 
centration of parasite eggs and is applicable to feces from a wide 
range of host animals, from canary birds to elephants. 

Standard Methods Apply Only to Human Feces 

There are many published methods for examining feces for par¬ 
asite eggs, but most of them are intended only for human feces, which 
is a very special case and some of them only for hookworm eggs, 
which again is a very special case. They are more or less elaborate, 
though sometimes very useful within the range of their applicability. 
For the purposes of the veterinarian the simpler technic given here 
and intended for feces of any sort and the detection of parasite eggs 
of any sort is recommended. 

In examining feces under the microscope for parasite eggs, one 
must use care not to mistake plant spores, plant hairs, etc., for eggs 
and worms. To this end it is necessary to consult the available text 
and reference books in regard to the eggs of the various parasites 
of the host animal up for examination. Unfortunately, the existing 
books do not lay much emphasis on egg sizes and shapes in all in¬ 
stances and it is sometimes difficult to get the desired information. 

The courses in parasitology in our veterinary colleges should con¬ 
tain enough work in fecal examination to make students reasonably 
familiar with the technic and the interpretation of the slides prepared, 
so that eggs found will at least be recognizable in a general way to 
students and to practitioners thus properly trained. 

Failure to find eggs in feces with any technic whatsoever is not 
conclusive proof that no worms are present. In very light infesta¬ 
tions the few eggs present in feces may not occur in the preparations 
examined; where only male nematodes are present there will be no 
eggs in the feces; where only larvae or young worms are present 
there will be no eggs; and egg production may be interrupted or termi¬ 
nated by old age, anthelmintics or accident. 


16 


The Eggs and Larvae of Dog, Cat 
and Fox Parasites 


I N previous pages, the subject of examining feces for parasites and 
parasite eggs has been discussed. It now seems advisable to follow 
this with some descriptions with illustrations of the parasite eggs 
present in the case of the dog, cat and fox. There has been some 
demand for something of the sort on the part of veterinarians, and 
in view of the scarcity of illustrations covering this point in text¬ 
books and the fact that the available illustrations are scattered 
through numerous publications largely inaccessible to the practitioner, 
there is evidently some reason for the demand. Strange as it may 


/l 


3 . 

Fig. 1. Taenia pisiformis. A, egg surrounded by vitelline membrane containing 
vitelline masses. B, embryophore. Enlarged. From Railliet, 1893. 




seem, the eggs of some of the commonest parasites have been figured 
but very seldom, presumably on the assumption that everyone in¬ 
terested in them is familiar with them, which is not a safe assump¬ 
tion. Some of the available figures are not very satisfactory, but 
material for new illustrations is not always available in these cases, 
and as the existing illustrations serve the purpose of at least indicat¬ 
ing something of the appearance of the egg in question, they have 
been copied here. 


17 






A number of the figures are taken from Railliet’s Traite de 
zoologie medicale, a work which has been for almost thirty years 
the most satisfactory reference book of veterinary parasitology. It 
is a matter for regret that this splendid work has never been issued 
in revised editions and brought up to date. At the present time it 
is almost impossible to purchase copies of the sole edition printed. 

In examining the feces of dogs, cats and foxes for parasite eggs, 
there are certain eggs which are very commonly present, and for this 
reason these eggs are figured here. However, it is the uncommon 



Fig. 2. Taenia hydatigena. A, egg as seen mounted in glycerine. B, egg after treat¬ 
ment with a concentrated potash solution, x 350. From Railliet, 

1893, after Laboulbene. 

thing which is most perplexing, and for this reason the eggs of some 
of the rarer parasites are also figured. Among the commoner species 
present are tapeworms of the genera Taenia and Dipylidium and 
nematodes of the genera Belascaris, Toxascaris, Ancylostoma and 
Trichuris. 

In the genus Taenia, the egg forms with a thin shell, with or 
without filaments, and the embryo, or onchosphere, lies inside of this 




Fig. 3. Echinococcus granulosus. Eggs, x 245. From Blanchard, 1889, after Krabbe. 

enclosed in a thick, radially striate shell called the embryophore. As 
found in the feces only the embryophore and the contained embryo, 
or onchosphere, are present as a rule. This embryophore is com- 
monly termed the egg and is so termed in this paper. The con¬ 
tained embryo is armed with six small hooks which may be seen 
without difficulty under the ordinary powers of the microscope. The 


18 


eggs of tapeworms of the genera Multiceps and Echinococcus are 
quite similar in structure. In view of the overlapping of the egg 
sizes of tapeworms in this group, it is not usually feasible to make 
a definite diagnosis in regard to the species of tapeworm present, but 



Fig. 4. Dipylidium caninum. Egg capsule. Enlarged. From Stiles, 1903. 

such a diagnosis is usually unnecessary anyway. The following figures 
cover briefly the eggs of some of the dog, cat and fox tapeworms. 

Taenia taeniaeformis (T. crassicollis) of cats, spherical, 31 to 37 
microns in diameter; T. pisiformis (T. serrata) (Fig. 1) of dogs and 



Fig. 5. Dipylidium caninum. Egg. Magnified. From Railliet, 1893, after Moniez. 

foxes, elliptical, 37 by 34 microns; T. hydatigena (T. marginata) 
(Fig. 2) of dogs, elliptical, 38 to 39 microns by 34 to 35 microns; T. 
ovis of dogs, 30 to 34 microns by 24 to 28 microns; Multiceps multi¬ 
ceps (T. coenurus) of dogs, spherical, 29 to 38 microns; M. serialis 



Fig. 6. Mesocestoides lineatus. Eggs, x 300. From Railliet, 1893. 

(T. serialis) of dogs, elliptical, 31 to 34 microns by 29 to 30 microns; 
Echinococcus granulosus (T. echinococcus) (Fig. 3) of dogs and cats, 
elliptical, 32 to 36 microns by 25 to 30 microns. 

The eggs of Dipylidium have two thin shells and are contained in 


19 



egg capsules formed by the breaking up of the reticular uterus. The 
number of eggs in a capsule varies with different species and may 
vary in one species. In the case of worms of this genus, one may find, 
in the feces of infested animals, segments, egg capsules or individual 
eggs. In D. caninum of dogs and cats, the egg capsule (Fig. 4) may 
contain 5 to 20 or more eggs, the egg (Fig. 5) being spherical, 43 to 
54 microns in diameter and with an onchosphere 25 to 36 microns in 
diameter. In D. sexcoronatum of dogs and cats, the egg capsule may 



Fig. 7. Diphyllobothrium latum. Egg. x 680. From Magath, 1919. 

contain 2 to 15 eggs, the eggs being spherical and 21 microns in 
diameter. 

The eggs of tapeworms of the genus Mesocestoides are ovoid and 
have two very thin shells. The egg of M. lineatus (Fig. 6), which 
appears to be identical with M. litteratus, of dogs, cats and foxes, is 
40 to 60 microns long by 35 to 43 microns wide. 

The eggs of Diphyllobothrium (Dibothriocephalus or Bothrioce- 
phalus) are elliptical and provided with a small operculum or lid at 



Fig. 8. Opisthorchis pseudofelineus. Egg. Enlarged. From Barker, 1911. 

one end. The egg of D. latum (Fig. 7) of dogs, cats and foxes is 
68 to 71 microns long by 44 to. 45 microns wide, according to texts. 
Magath finds a range of 55 to 76 microns in length by 41 to 56 
microns in width. In general the figures given here for egg sizes are 
those given in texts. As a matter of fact, careful measurement of a 
large number of eggs will usually show some eggs which lie outside of 
the range of measurement given. 

Fluke eggs are usually more or less oval in shape, with an 


20 


operculum or lid at one end. Opisthorchis pseudofelineus (Fig. 8) 
of cats has an egg 29 to 36 microns long by 14 to 16 microns wide. 

Nematode eggs are very variable in shape and in the amount of 
development at the time they are deposited. Some of the more com¬ 
mon are discussed below. 



Fig. 9. a, b, Toxascaris limbata. Eggs, e. With developed embryo, 
c, d, Belascaris marginata. Eggs. Enlarged as indicated. From Wigdor, 1918. 

In the genus Belascaris, the eggs are more or less globular to 
elliptical, with a thin pitted shell. In B. marginata of the dog, the 
eggs (Fig. 9) are 72 to 104 microns long by 50 to 78 microns wide. 
In B. mystax of the cat, the eggs are more or less oval and 65 to 75 
microns long. 



Fig. 10. Ancylostoma caninum. Eggs in various stages of development, x 300. 

From Railliet, 1893. 

In the genus Toxascaris, the eggs are ellipsoidal, clear and smooth 
in appearance, with an outer clear, double-contoured chitinous shell 
and an inner yellowish membrane with interlaced striations giving 
the appearance of fibres. In T. limbata of the dog and fox, the egg 
(Fig. 9) is 72 to 104 microns long by 64 to 80 microns wide. As 


21 







deposited by the female worm and as found in the feces, the ascarid 
eggs (Ascaris, Belascaris, Toxascaris, etc.) show little trace of in¬ 
ternal development and some little time is necessary for the formation 
of the embryo in the shell. Where eggs are found containing developed 
embryos, it may be taken as evidence that they are not actually from 
fresh feces but from older material which may contaminate fresh feces 
collected from an area not properly cleaned before the collection of the 
fresh sample. 



Fig. 11. Trichuris depressiuscula. Egg. x 340. From Riley and Fitch, 1921. 


The hookworm eggs are elliptical, thin-shelled and usually found 
with the contents in a state of segmentation. In Ancylostoma caninum 
of dogs, cats and foxes, the eggs (Fig. 10) are 74 to 84 microns long 
by 48 to 54 microns wide. In Uncinaria stenocephala of dogs, cats 
and foxes, the eggs are 63 to 67 microns long by 32 to 38 microns wide. 

Whipworm and hairworm eggs are characteristically lemon-shaped, 



Fig. 12. Dioctophyme renale. A, egg showing shell surface with markings. B, egg 
showing embryo and optical section of shell, x 250. From Railliet, 1893. 


with an opercular plug at each end. In Trichuris depressiuscula 
(T. vulpis) of the dog and fox, the eggs (Fig. 11) are 72 to 80 microns 
long, according to Railliet, or 77 to 86 microns long, according to 
measurements of American material, by 37 to 40 microns wide. In 
T. campanula of the cat, the eggs are 72 microns long by 34 microns 


22 


wide. In Capillaria felis-cati of the cat, the eggs are 61 to 64 microns 
long by 27 to 32 microns wide. This species occurs in the urinary 
bladder, the eggs passing in the urine. Eggs passing in the urine are 
quite likely to be found in the feces as a result of contamination. 
In C. aerophila of the dog, cat and fox, the eggs are 67 to 72 microns 



Fig. 13. Echinopardalis pardalis. Egg. Enlarged. From Travassos, 1917. 


long. This species occurs in the air passages of the lungs and the 
eggs pass out in the feces. The eggs of this species should be care¬ 
fully differentiated from those of the whipworm in examining feces 
from foxes, as this is a common parasite of foxes in North America. 

The eggs of the kidney worm of the dog and fox, Dioctophyme 



Fig. 14. Linguatula serrata. Egg. Enlarged. From Fiebiger, 1912, after Csokor. 


renale (Fig. 12), are ellipsoid, brownish, have a thick shell marked 
with numerous depressions, and are 64 to 66 microns long by 40 to 44 
microns wide. When the female worm is in the kidney, the eggs pass 
in the urine and may be found in feces as a result of contamination. 


23 









When the female is in the body cavity, the eggs are passed into the 
abdominal cavity and are largely picked up by the omentum in its role 
of protector against foreign objects. 

Acanthocephalids, or thorny-headed worms, are rare in dogs and 
cats, but they sometimes occur, and one species, Oncicola canis, has 
been found in the United States. The eggs have three shells. The 
eggs of Echinopardalis pardalis (Fig. 13) of the cat are 53 to 63 microns 


Fig. 15. Synthetocaalus abstrusus. Larva, x 150. From Railliet, 1893. 

long by 38 to 42 microns wide. The egg sizes for O. canis do not 
appear to have been reported. 

The tongue worm, Linguatula serrata, occurs in the nasal cavities 
of the dog, fox and other animals. The egg (Fig. 14) is elliptical, 
90 microns long by 70 microns wide, and contains an embryo when 
deposited; the embryo has two pairs of bifurcated appendages. The 
eggs of the tongue worm, which is regarded as a degenerate arachnid. 

A. B C. 



Fig. 16. Sarcopies scabiei. Eggs in various stages of development, x 150. 

From Railliet, 1893. 

are expelled in sneezing, but probably some of them are swallowed 
and pass in the feces. This parasite has been reported only once from 
the dog in the United States. 

In the case of certain nematodes, such as some of those occurring 




24 


























ill the lungs, the eggs do not pass in the feces, but hatch in the body 
of the host animal. In such cases larvae are found in the feces. An 
illustration of this is the cat lungworm, Synthetocaulus abstrusus. The 
eggs of this worm develop in the alveoli of the lungs and the young 
worms hatch, make their way up the trachea and are swallowed, ap¬ 
pearing in the feces as larvae (Fig. 15). 

Numerous objects, such as plant spores, simulate parasite eggs in 
feces to some extent. Among other things which may be present 
and which must be eliminated from consideration as worm eggs, are 
the eggs of mites, both parasitic and free-living. An illustration of 
the eggs of a sarcoptic mite- (Fig. 16) is given here. These eggs are 
elliptical and rather large, being in the case of Saroptes scabiei canis 
of the dog about 150 microns long by 80 microns wide. In an early 
stage the contents of the egg are granular; later the development of 
the mite in the egg makes an identification easy. 


25 



The Eggs and Larvae of Swine 
Parasites 

In view of the fact that one of the protozoan forms is very com¬ 
monly present in swine feces and may be mistaken for a parasite egg, 
this form is briefly noted here. It is Balantidium coli, one of the 
ciliates. In fresh feces it may be found actively moving about, in which 
case it will resemble the parasite as figured here (Fig. 17). In older 
feces it is found encysted and is then much more suggestive of a 
parasite egg. 

Tapeworms are rarely found in swine and can not be regarded as 
normally parasitic in this host. The few records we have of these 



Fig. 17. Balantidium coli. Enlarged. From Gedoelst, 1912, after Leuckart. 

worms from swine indicate, for the most part, that they are present as 
a result of the swine having eaten entrails of sheep or other animals, 
the swine being slaughtered shortly afterwards while the worms were 
yet present and undigested, or that the worms had developed in the 
swine but had failed to attain the normal development attained in the 
usual host, the worms being sterile. In view of this fact, the injunc¬ 
tions occasionally published by some writers, advising the feeding of 


26 













pumpkin seed or other vermifuges to swine to remove tapeworms, are 
not well taken. 

Of the flukes present in swine in this country, the common liver 
fluke, Fasciola hepatica, which occurs in swine, sheep and cattle, may 
be left for consideration in connection with the parasites of sheep, the 




Fig. 18. Paragonimus westermani. Eggs from mucus in lungs, x 475. 

From Ward and Hirsch, 1915. 

usual hosts. The lung fluke, Paragonimus westermani, is not un¬ 
common in swine in some parts of the United States, including parts 
of Texas, Oklahoma and Louisiana. The form in swine has been 
called P. kellicotti, as a different species from that in man, but the 



Fig. 19. Ascaris lumbricoides. Egg. Enlarged. From Leuckart, 1868. 

Japanese writers regard the forms from man and swine as identical. 
The eggs are coughed up and probably swallowed, as a rule, passing 
out in the manure. These eggs (Fig. 18) are 78 to 96 microns long 
by 48 to 60 microns wide, with an operculum or lid at one end. 

Of the nematodes of swine, probably the most important, as a 
rule, is the ascarid, regarded by most authorities at present as identical 


27 






with the common ascarid of man, Ascaris lumbricoides, though yet 
discussed in many texts as A. suilla. The eggs (Fig. 19) of this worm 
are from 56.5 to 87.5 microns long by 46.5 to 57.5 microns wide; they 



Fig. 20. Arduenna strongylina. Egg. From Foster, 1912. 

are elliptical, with thick, transparent shells surrounded by a thick layer 
of albumen which is irregularly mammilated and yellow, and are not 
segmented when deposited. 



There are two species of spirurid worms, Arduenna strongylina 
and Physocephalus sexalatus, which are not uncommon in ,the stomach 


28 













ot swine. The egg of Arduenna strongylina (Fig. 20) is elliptical, 
34 to 39 microns long by 20 microns wide, thick-shelled, the shell sur¬ 
rounded by a thin irregular membrane, and contains a well developed 
embryo when deposited. The egg of Physocephalus sexalatus (Fig. 
21) is elliptical, 34 to 39 microns long by 15 to 17 microns wide, thick- 
shelled, the shell surrounded by a thin irregular membrane, and con¬ 
tains a well developed embryo when deposited. 

The eggs of the swine whipworm, Trichuris suis, are 52 to 56 microns 
long, brown, and lemon-shaped, as in the case of other species of the 
genus Trichuris, such as Tr. depressiuscula, which was figured (Fig. 11) 
on page 20. In the case of a closely related 'and highly important 
worm, Trichinella spiralis, which occurs in swine, eggs and larvae are 
not found in the feces, as the eggs, which have a delicate vitelline 
membrane but no true egg shell, hatch in the maternal uterus and 



Fig. 22. Crassiosoma urosubulatum. Eggs. Enlarged. From Alessandrini, 1909. 

the larvae migrate through the tissues of the host, the parasite being 
transmitted by new hosts eating meat infested with these larvae and 
not through the medium of the feces. 

Swine in this country and elsewhere are infested occasionally by 
a worm belonging in the group of hookworms. This swine hookworm 
is known as Globocephalus longemucronatus or Crassiosoma urosubu¬ 
latum. The description applied to the worm under the first of these 
names does not appear to conform to the description given for the 
worm described under the second name, but the points of agreement 
are such that it is possible that they are identical. The eggs (Fig. 22) 
of this worm are elliptical and 52 microns long by 35 to 36 microns wide. 
In this connection it is of interest to note that the Old World hook¬ 
worm of man, Ancylostotna duodenale, has been reported from swine 
in the Ellice Islands by O’Connor and that Legg and Reuben state that 
they find it relatively common in swine in Queensland, Australia. Ran¬ 
som has recently reported the occurrence of three specimens of the dog 


29 


and fox hookworm, Uncinaria stenocephala, from the stomach of a 
pig in Canada, and notes that there are specimens of Bunostomum 



Fis 23. Stephamirus dentatus. Egg, containing embryo. Enlarged. 

B From Taylor, 1900. 

trigonocephalum, the sheep hookworm, labeled as collected from the 
pig, in the collections of the Federal Bureau of Animal Industry. 
A new species of hookworm from swine in the Island of Trinidad 


Fig. 24. Gnathostoma hispidum. Egg. x 700. From Ciurea, 1911. 

has just been described by Ackert and Payne under the name of 
Necator suillus. The eggs are 56 to 66 microns long by 35 to 40 
microns wide. 

The eggs of the nodular worm of swine, CEsophagostomum 
dentatum, are similar in shape to those of the hookworms and are 
60 to 80 microns long by 35 to 45 microns wide. Another nodular 
worm, Bourgelatia diducta, has been described from swine in Annam. 
The eggs are ellipsoidal, 69 to 77 microns long by 38 to 43 microns 
wide, and in the morula stage when deposited. 

30 





The eggs of the kidney worm of swine, Stepiianurus dentatus 
(Fig. 23), are elliptical, 100 to 120 microns long by 55 to 56 microns 
wide, thin-shelled, and segmenting when deposited. These eggs pass 



Fig. 25. Strongyloides stercoralis. Rhabditiform larva from fresh feces, x 310. 
From Stephens, 1916, after Looss. 


out in the urine, but may be found in the feces as a result of mixing 
urine and feces. 

The eggs of the small red stomach worm of swine, Hyostron- 
gylus rubidus (Strongylus rubidus) are elliptical, 45 microns long by 
36 microns wide, and segmenting when deposited. 



Fig. 26. Strongyloides stercoralis. Mature filariform larva, x 620. 
From Stephens, 1916, after Looss. 



An interesting nematode of swine which has not yet been reported 
from the United States is Gnathostoma hispidum. The eggs (Fig. 24) 
are 70 to 74 microns long by 39 to 42 microns wide, the shell marked 
with small depressions and with a wart-like projection or plug at 
one pole; segmentation begins in the anterior portion of the maternal 

uterus. 


31 





There are two species of lungworms, belonging in the genus 
Metastrongylus, in swine, these being M. elongatus and M. brevivagijua- 
tus. The eggs of these worms hatch in the lungs and the larvae are 
coughed up and swallowed, as a rule, the larvae passing out in the 
feces. The larvae of M. elongatus are 220 to 350 microns long by 10 
microns wide, clear anteriorly and granular posteriorly, and with a 
knob-like tail. 

The larvae of these lungworms must be distinguished from those 
of worms of the genus Strongyloides. Members of this genus occur 
as parasitic females which are parthenogenetic, no males being found. 
The eggs passing out in the feces usually contain embryos, which soon 
hatch under ordinary conditions, giving rise to rhabditiform larvae. 
These rhabditiform larvae may then give rise to filariform larvae, 



Fig. 27. Macracanthorhynchus hirudinaceus. Egg. Enlarged. From Travassos, 1917. 

capable of reinfesting host animals, or may develop to free-living adult 
males and females, which reproduce and give rise to rhabditiform 
larvae, which later develop to infective filariform larvae. One species 
which has been described from swine is Strongyloides suis. Another 
species which is reported from swine is the one found in ruminants, 
Str. papillosus. Ackert and Payne have recently reported the form 
from man, Str. stercoralis, from swine in the Island of Trinidad. The 
rhabditiform larva (Fig. 25) and the filariform larva (Fig. 26) of the 
human Strongyloides are figured here. 

The eggs (Fig. 27) of the thorny-headed worm of swine, 
Macracanthorhynchus hirudinaceus (Gigantorhynchus gigas) are oval, 
90 to 100 microns long by 51 to 56 microns wide, and provided with 3 
shells; the embryo is coiled up and has at the anterior end 4 large 
hooks and a number of smaller ones. 


32 







The Eggs and Larvae of Cattle, 
Sheep and Goat Parasites 


HESE host animals are infested with a number of tapeworms be- 



-L longing to the group which includes the unarmed tapeworms, or 
those in which the head or scolex is not provided with hooks. So far 
as can be judged from the literature, goats are less subject to tape¬ 
worm infestation than are sheep and cattle. Tapeworms are often 
found in the small intestine of ruminants, the usual site for tapeworms 



Fig. 28. Moniezia planissima. Egg. Enlarged. From Stiles and Hassall, 1893. 

in general, but in some cases they are found in the ducts of the liver 
and pancreas, in the gall bladder and, rarely, in the stomach, as in the 
case of Thysanosoma actinioides of sheep, this being the fringed tape¬ 
worm found in sheep in the western United States. Stilesia hepatica 
occurs in the biliary ducts of the liver in sheep and goats and in the 


33 







stomach of cattle, and Avitellina centripunctata is reported from the 
stomach of cattle and the small intestine of sheep. 

The eggs of tapeworms belonging to the genus Moniezia are thin- 
shelled and the embryo has, in place of the radially striate embryophore 
of the taenioid cestodes, a special structure called the piriform ap¬ 
paratus. In its most highly developed condition this consists of a 
central bulb surrounding the onchosphere, with two so-called horns 
extending from the bulb and terminating in a disk. The diameter of 
the eggs of some of the commoner species of Moniezia are as follows: 



Fig. 29. Fasciola hcpatica. Egg containing embr/o, or miracidium. Enlarged. 
From Fiebiger, 1912, after Csokor. 


M. expansa, 50 to 60 microns; M. planissima (Fig. 28), 63 microns; 
M. trigonophora, 52 to 60 microns. The eggs of Thysanosoma 
actinioides are 70 to 105 microns long by 35 to 58 microns wide; the 
piriform body is without horns in this species. In examining feces of 
ruminants for evidences of tapeworm infestation, it appears probable 
that one will usually find gravid segments containing the eggs of the 
tapeworms present rather than free eggs released from the segments. 
The gravid segments of Moniezia are wider than long; those of Thy¬ 
sanosoma tend to show a triangular outline when viewed dorso-ven- 


34 






trally, the anterior margin of the segment contracting to a blunt point 
and the posterior margin displaying the fringe-like structure present 
on the posterior margin of every segment of the worm. 



Fig. 30. Fascioloides magna. Egg. Enlarged. From Stiles, 1894. 

There are few flukes known to occur in ruminants in the United 
States. The most important one is the common sheep liver fluke, 



Fig. 31. Dicrocoelium dendriticum. Egg. Enlarged. From Fiebiger, 

1912, after Csokor. 

Fasciola hepatica, which occurs in sheep, goats, cattle and swine. 
It is rarely present in horses and then usually in young animals. 
The eggs (Fig. 29) are 130 to 145 microns long by 70 to 90 microns 


35 








wide, yellowish-brown, and with an operculum, or lid, at one end. 
The larger liver fluke of cattle, Fascioloides magna (Fasciola magna), 
has been reported but rarely from sheep. The eggs (Fig. 30) are 140 
to 160 microns long by 90 to 100 microns wide, brown, and operculated. 



Fig. 32. Schistosoma bovis. Egg. Enlarged. From Railliet, 1893, after Sonsino. 

The giant liver fluke, Fasciola gigantica, reported from the Philippines, 
has eggs 125 to 175 microns long by 60 to 100 microns wide. Dicrocoe- 
lium dendriticum (Dicrocoelium lanceatum), a fluke common in 
Europe, but not yet reported from the United States, has eggs (Fig. 31) 



Fig. 33. Gongylonema scutatum. Egg containing embryo. Enlarged. From Stiles, 1892. 

38 to 45 microns long by 22 to 30 microns wide. The conical 
amphistome, Paramphistomum cervi (Amphistoma conicum), occurs 
in the rumen and reticulum of cattle and other ruminants and is 
sometimes found in these animals in the United States. The eggs are 


36 



155 to 162 microns long by 82 to 90 microns wide, thickened at one 
pole and operculated at the other. Schistosomes, a group of flukes 
inhabiting the blood-vessels, have not yet been reported as present in 
domesticated animals in the United States. The eggs of these flukes 
are usually much elongated. In the bovine blood fluke, Schistosoma 
bovis, the eggs (Fig. 32) are 160 to 180 microns long by 40 to 50 
microns wide, with a pronounced swelling in the middle and armed 


Fig. 34. Gaigeria pachyscelis. Eggs. Enlarged. From Gaiger, 1911. 



with a pointed spine at each end. In the case of this species, the eggs 
may pass in the manure and in the urine, as the veins both of the 
rectum and of the bladder may be inhabited by the flukes. 

Ruminants are infested by a large number of species of nematodes, 
some of which occur in the digestive tract or respiratory tract with 
the evidence of their presence in the form of eggs and larvae in the 
feces, and some of which occur in the blood, body cavity and various 
tissues and which cannot be determined as present by fecal examina¬ 
tions. 


37 




Two of the swine parasites of which the eggs were figured in the 
previous article in this series, namely, Arduenna strongylina and 
Physocephalus sexalatus, have recently been reported as accidental 
parasites of cattle in the United States by Dikinans, and another 
swine parasite, the kidney worm, Stephanurus dentatus, has been re¬ 
ported from cattle by Hall. The gullet worm of cattle, sheep and 
goats, occasionally present in horses, Gongylonema scutatum, has an 
egg (Fig. 33) 56 to 60 microns long by 32 to 36 microns wide, con¬ 
taining at the time of oviposition an embryo provided with a hook-like 
process on one side near the anterior end, the opposite side of the 
anterior end of the worm showing an annulate marking. The eggs 



Fig. 35. Haemonchus contortus. Eggs in various stages of development, x 380. 

From Veglia, 1916. 


of another gullet worm, G. verrucosum of sheep and goats, are 45 to 
50 microns long by 25 to 27 microns wide. The eggs of the cattle 
ascarid, Ascaris vitulorum, are 75 to 80 microns in diameter. The 
ascarids found in sheep appear to be specimens of Ascaris lumbricoides 
of man and swine, present as accidental parasites in an unusual host 
and quite generally incompletely developed and devoid of eggs, or at 
least of fertile eggs. 

The eggs of the numerous strongyles occurring in the digestive 
tract of ruminants are commonly more or less elliptical and thin- 
shelled. Although the egg sizes overlap in many cases to such an 
extent that it is often impossible to determine the species present, a 
reasonable probability as to the presence of certain worms may be 


38 




established in the case of some worms. Haemonchus contortus is so 
commonly present that the presence of eggs falling within the size 
range for this species may be taken as a fairly safe indication that this 
worm is present. 

The egg sizes in microns for some of the larger strongyles, those 
having a well developed mouth capsule and belonging to the family 
Strongylidae, are as follows: The cattle hookworm, Bustomum 
phlebotomum, 75 to 98 long by 40 to 50 wide; the sheep hookworm, 
Bunostomum trigonocephalum, 75 to 83 long by 38 to 45 wide; the 
cattle nodular worm, Proteracrum radiatum, 75 to 85 long by 40 to 50 
wide; the common sheep nodular worm, Proteracrum columbianum, 65 


Fig. 36. 



Trichuris ovis. Eggs. 




Enlarged. From Fiebiger, 1912, after Csokor. 


to 75 long by 40 to 45 wide; the goat hookworm, Proteracrum asperum, 
reported from the Canal Zone, 83 to 85 long by 55 to 60 wide; the 
veined nodular worm of sheep, Hysteracrum venulosum, 85 to 90 long 
by 45 to 55 wide; the sheep and goat nodular worm, Gaigeria pachyscelis 
(Fig. 34), reported from India and the Belgian Congo, 105 to 118 long 
by 50 to 55 wide; the strongyle from the large intestine of ruminants, 
Chabertia ovina, 90 to 100 long by 50 wide. 

The egg sizes in microns for some of the trichostrongyles, which 
are the smaller strongyles, those without a well developed mouth 
capsule and belonging in the family Trichostrongylidae, are as follows: 


39 








The common stomach worm, Haemonchus contortus (Fig. 35), 75 to 95 
long by 40 to 50 wide; H. similis, reported from the United States by 
Dikmans, 70 to 78 long by 35 to 42 wide; Ostertagia ostertagi, 65 to 80 
long by 30 to 40 wide; O. circumcincta, 75 to 100 long by 35 to 50 wide; 
O. trifurcata, 85 to 95 long by 40 to 48 wide; O. marshalli, 160 to 200 
long by 75 to 100 wide; O. bullosa, 85 long by 65 wide; Cooperia 
punctata, 65 to 72 long by 30 wide; C. oncophora, 60 to 80 long by 30 
wide; C. pectinata, 70 to 80 long by 36 wide; C. curticei, 63 to 70 
long by 30 to 32 wide; Nematodirus filicollis, 130 to 200 long by 70 to 
95 wide; N. spathiger, 150 to 220 long by 80 to 110 wide; N. abnormalis, 
160 to 230 long by 85 to 115 wide; Trichostrongylus extenuatus, 70 to 
80 long by 35 to 45 wide; T. colubriformis, 73 to 80 long by 40 to 43 



Fig. 37. Capillaria brevipes. Egg. Enlarged. From Ransom, 1911. 

wide; T. probolurus, 76 to 80 long by 43 to 46 wide; T. vitrinus, 84 to 
90 long by 46 to 50 wide; T. capricola, 75 to 95 long by 35 to 45 wide. 

The Y-worm of cattle and carabao, Syngamus laryngeus, a relative 
of the gapeworm of poultry, has been reported from the Philippines 
by Hall and has recently been reported by Ransom and by Bague 
from Porto Rico. The eggs of this worm are 80 microns long by 
40 microns wide. 

The eggs of the common whipworm of ruminants, Trichuris ovis 
(Fig. 36), are lemon-shaped and 70 to 80 microns long by 30 to 35 
microns wide. Those of the hair-worms, belonging to the genus 
Capillaria, are also lemon-shaped, the dimensions for the various 


40 





species being as follows: Capillaria bovis of cattle, 47 microns long 
by 27 microns wide; C. brevipes (Fig. 37) of sheep, 50 microns long 
by 25 microns wide; C. longipes (Fig. 38) of sheep, 45 to 50 microns 
long by 22 to 25 microns wide. 



Fig. 38. Capillaria longipes. Egg. Enlarged. From Ransom, 1911. 

As noted in the paper on eggs and larvae of swine parasites, the 
eggs of species of the genus Strongyloides contain well developed 
embryos when passed, and these eggs hatch promptly. The eggs may 
be found in fresh feces, but in older feces the free larvae are present. 



Fig. 39. Synthetocaulus capillaris. Larva. Enlarged. From Fiebiger, 1912. 

Brumpt, in 1921, reported a new Strongyloides, S. vituli, from cattle, 
but no description of this species is yet available. The eggs of S. 


41 





papillosus of sheep and goats are 40 to 60 microns long by 20 to 25 
microns wide. The rhabditiform larvae and the filariform larvae are 
similar in a general way to those of S. stercoralis, figured in the 
paper on eggs and larvae of swine parasites. 

As previously noted, the eggs of the lung-worms belonging to the 
family Metastrongylidae hatch in the lungs and the larvae ascend the 
trachea and are usually swallowed, passing out in the manure. The 
larvae of the common lungworm of cattle, Dictyocaulus viviparus, are 
280 microns long by 25 microns wide when first hatched; these larvae 
have a button-like head and a rather blunt tail. The larvae of the 
common sheep lungworm, D. filaria, are somewhat similar. The larvae 
of the hair lung-worm of sheep, Synthetocaulus rufescens, are 300 to 
400 microns long by 16 to 18 microns wide and have a tail prolonged 
by an undulate appendix. The larvae of S. capillaris (Fig. 39) are 
similar and are 230 to 300 microns long by 20 microns wide. 


42 



The Eggs and Larvae of Horse 
Parasites 


I N general the parasites infesting horses infest asses and mules also. 

Horses are infested with three species of tapeworms, all of them 
having heads which are not provided with hooks and all of them 



Fig. 40. Anoplocephala perfoliata. Egg. x 360. From Yorke and Southwell, 1921. 


occurring in the United States. The eggs of the tapeworms are 
provided with a piriform apparatus such as was described in the 
previous paper on eggs and larvae of ruminant parasites. The egg of 



Fig. 41. Schistosoma indicum. Egg. Enlarged. From Skrjabin, 1913. 

Anoplocephala magna is described as oval, round or polyhedral, and is 
about 88 microns long by 50 to 60 microns wide. The egg of A. 
perfoliata (Fig. 40) is approximately spherical and is 65 to 80 microns 


43 



in diameter. The egg of A. mamillana is 50 to 60 microns in diameter 
according to some writers; Fiebiger states that it is oblong. 

Of the flukes infesting the horse, Fasciola hepatica, Fascioloides 
magna and Dicrocoelium dendriticum have already been considered 
in previous papers. In India the horse is infested with a blood fluke, 
Schistosoma indicum, the eggs passing in the manure and in the urine. 
The egg (Fig. 41) is oval, with a spine at one end. In the fluke these 
eggs are from 92 to 100 microns, rarely 112 microns, long by 42 to 
44 microns, rarely 52 microns, wide, with a spine 13 to 14 microns 
long; eggs from the rectum of horses are 120 to 140 microns, rarely 
152 microns, long by 68 to 72 microns wide. The remaining flukes 
reported from horses are mostly amphistomes, flukes having an oral 



Fig. 42. Gastrodiscus aegyptiacus. Eggs, x 100. From Railliet, 1893. 

sucker at the anterior end and having the ventral sucker or acetabulum 
at the posterior end. Of these, Gastrodiscus aegyptiacus has ovoid 
eggs (Fig. 42) 150 to 170 microns long by 90 to 95 microns wide, ac¬ 
cording to some writers, or 170 to 190 microns long by 110 microns 
wide, according to Looss. The eggs of G. secundus are 150 to 160 
microns long by 90 to 100 microns wide. The eggs of Pseudodiscus 
collinsi and Ps. stanleyi do not appear to have been observed as yet. 

There are numerous nematodes infesting the horse. Among these 
is a species of Strongyloides, S. westeri, which is so far reported only 
from Holland. The life history of this worm is similar to those of 
species of Strongyloides referred to in previous papers; the eggs hatch 

44 


soon after their passage from the host and if manure is not examined 
promptly after it is passed, larvae will be found instead of eggs. The 
eggs of S. westeri are thin-shelled, 40 to 52 microns long by 32 to 40 
microns wide, deposited in strings, similar to those described by 
Ransom for S. ovocinctus from the prong-horned antelope. The 
rhabditiform larva is 495 to 525 microns long by 15 to 20 microns wide. 

Among the most important of the spirurid worms of the horse are 
the stomach worms belonging to the genus Habronema. The eggs of 
H. muscae (Fig. 43) are thin-shelled and are 40 to 50 microns long by 



Fig. 43. Habronema muscae. Eggs, a, b, c, d, early stages of development; e, con¬ 
taining embryo doubled on itself; f, with embryo almost straightened out; 
g, h, i, with flexible egg shell applied to embryo in a manner 
resembling that of a cuticle. From Ransom, 1913. 

10 to 12 microns wide in an early stage of development in the uterus. 
As the embryo develops the egg becomes longer and at a stage where 
the embryo is doubled on itself is 87 microns long and about the same 
width as given above. Later the shell becomes closely applied to the 
embryo except in the tail region and in this stage the shell is very 
suggestive of a cuticle. The embryos are 85 to 100 microns long by 
5 to 7 microns wide, with a rounded anterior end. The eggs of H. 
microstoma are oblong and truncate, and are 45 to 49 microns long 
by 16 microns wide. The embryo is 90 to 98 microns long. The eggs 
of H. megastoma are elongate, 40 to 57 microns long by 10 to 18 


45 





microns wide, according to Hill. Railliet states in his Traite that 
these eggs are 330 to 350 microns long by 8 microns wide, and these 
measurements have been copied by subsequent authors, but apparently 
the figures for length here have been multiplied as the result of a 
shifted decimal point due to a printer’s error or a lapsus of some sort. 
Hill states that the embryo is about 104 microns long, whereas Railliet 
states that it is 600 to 700 microns long, perhaps as the result of a 
lapsus similar to that in the case of the egg measurements. Gon- 
gylonema scutatum, the gullet worm of sheep and cattle, occurs in 
horses also, and has been collected by the writer from the horse at 
Bethesda, Maryland. Physocephalus sexalatus, one of the stomach 
worms of swine, has been reported from the ass by Seurat, but the 



Fig. 44. Strongylus vulgaris. Egg. Enlarged. From Winchester, 1892. 


description of his specimens does not agree in all respects with the 
description of P. sexalatus and it seems advisable to reserve judgment 
in regard to the occurrence of this worm in the horse for the present. 

Dioctaphyme renale (Fig. 12), the giant kidney worm of the dog, 
has been reported at least four times from the horse by various writers. 

In spite of the fact that the numerous strongyles in the large 
intestine of the horse constitute the most important group of worm 
parasites of the horse, there is an astonishing scarcity of figures of the 
eggs and of egg measurements. It is of great interest to note that the 
only figure of one of these strongyle eggs which has been found by 
the present writer is one published by the late Dr. J. F. Winchester 
thirty years ago. This egg (Fig. 44), like the remainder of Win¬ 
chester’s figures, is labeled Strongylus armatus, but the other figures 
are evidently figures of S. vulgaris, and the sizes he gives for the egg, 
92 microns long by 54 microns wide, appear to be correct for S. vulgaris. 


46 


Winchester s paper is an excellent piece of work, giving excellent 
illustrations of S. vulgaris eight years before Looss in Egypt definitely 
separated out and named this species. It shows what good work the 
practicing veterinarian can do along investigational lines when he has 
the time, the inclination and the taste for painstaking work. 



Fig. 45. Dictyocaulus arnfieldi. Larvae, the one at the left in the process of leaving 
the egg shell, x 150. From Railliet, 1893. 

The eggs of the other strongyles of the large intestine of the horse 
are probably similar in a general way to those of S. vulgaris in 
appearance. The egg dimensions which have been published are as 
follows: Cylicostomum euproctum, 80 to 100 microns long by 50 to 60 
microns wide; C. insigne, 75 to 86 microns long by 45 to 50 microns 
wide; C. goldi, 100 microns long by 50 microns wide; CEsophagodontus 
robustus, 100 to 130 microns long by 50 to 60 microns wide; Triodonto- 
phorus minor, 87 microns long, according to some writers, or 80 to 
90 microns long by 40 to 50 microns wide, according to Boulenger; 
Tr. serratus, 130 microns long; Tr. intermedius, 90 to 100 microns long 
by 40 to 50 microns wide; Tr. tenuicollis, stated as similar to those 
of Tr. intermedius; Tr. brevicollis, 90 to 100 microns long; Acheilos- 
toma paranecator, 63 to 64 microns long by 43 microns wide. The egg 


47 





of the small trichostrongyle, Trichostrongylus axei, from the stomach 
of the horse, is 100 to 112 microns long by 63 microns wide, according 
to most writers; Wolffhuegel says the eggs from Argentine specimens 



Fig. 46. Ascaris equorum. Eggs, x 130. From Railliet, 1893. 

are 80 microns long by 25 microns wide, a discrepancy that calls for 
further investigation. 

The egg of the horse lungworm, Dictyocaulus arnfieldi (Fig. 45) is 
80 to 100 microns long by 50 to 60 microns wide and contains an em¬ 
bryo when deposited. These eggs hatch in the lungs and the larvae 
ascend the trachea, passing out in the manure. The larvae (Fig. 45) 



Fig. 47. Oxyuris equi. Eggs, x 200. From Railliet, 1893. 

are 400 to 490 microns long by 14 to 18 microns wide, with a thin 
transparent caudal appendix. 

The eggs of the horse ascarid, Ascaris equorum (Fig. 46) are 
almost globular, 90 to 100 microns in diameter, and are not segmenting 
when deposited. The egg of the pinworm, Oxyuris equi (Fig. 47), is 
85 to 95 microns long by 40 to 45 microns wide, asymmetrical, some¬ 
what flattened on one side, and provided with a clearly defined struc¬ 
ture resembling an operculum or lid at one end. The eggs of the 
viviparous pinworm of the horse, Probstmayria vivipara, a species oc¬ 
curring in the United States, Europe and elsewhere, are elongate oval, 
58 to 100 microns long by 40 to 75 microns wide. 


48 




The Eggs and Larvae of Poultry 
Parasites 


HE eggs of most of the flukes occurring in poultry are of the 



usual elliptical shape and provided with an operculum at one 


end. Some of the egg sizes in microns are as follows: Typhlocoelum 
obovale (duck; trachea, bronchi, lungs, etc.), 154 to 180 by 90; Trache- 
ophilus sisowi (duck; air passages of lungs), 122 by 63; Opisthorchis 
simulans (duck; biliary canals), 28 by 16 to 18; Metorchis xanthosomus 
(duck; biliary canals), 27 to 32 by 14; Echinostoma revolutum (duck, 



Fig. 48. Echinostoma revolutum. Eggs in various stages of development, x 34. 

From Johnson, 1920. 

goose, swan, chicken; intestine; U. S.), 94 to 114 (Fig. 48); E. recur- 
vatum (duck, chicken; intestine), 110 by 80; Hypoderaeum conoideum 
(duck, goose, chicken; intestine), 95 to 108 by 61 to 68; Prosthogonimus 


49 






cuneatus (chicken, peafowl; bursa of Fabricius; U. S.), 22 to 27 by 
13 to 16; P. ovatus (chicken; bursa of Fabricius and oviduct), 22 to 24 
by 13; P. intercalandus (chicken; oviduct and body cavity), 29 by 15; 
P. pellucidus (chicken; bursa of Fabricius and oviduct), 27 to 29 by 
11 to 13; P. japonicus (chicken; probably bursa of Fabricius), 24 by 12; 
Strigea gracilis (duck; intestine), 110 by 67; Cyathocotyle orientalis 
(duck; ceca and small intestine), 100 by 65. 



Fig. 49. Catatropis verrucosa. Eggs, x 215. From Neumann, 1909, after Dujardin, 

Some fluke eggs are not of the conventional shape given above. 
The eggs of Catatropis verrucosa (Fig. 49) are elliptical, 23 microns 
long by 11 microns wide, with a filament 160 microns long at each 
pole; this fluke occurs in the cecum and rectum of the goose. The 



F'ig. 50. Choanotaenia infundibulum. Eggs, x 425. From Guberlet, 1916. 

eggs of Bilharziella polonica are elongate anteriorly and have a small 
terminal spine posteriorly; this fluke occurs in the blood vessels of 
the duck. 

There are many species of tapeworms which occur in the intestines 
of poultry. A very small number of these belong to the group of 


50 




bothriocephalic! worms and as such have thick-shelled eggs with an 
operculum or lid at one end. Such an egg has already been figured 
in a previous paper for a related worm, Diphyllobothrium latum, one 
of the dog tapeworms. Schistocephalus solidus, a tapeworm from the 
intestine of the duck, has similar eggs, the eggs being 44 to 54 microns 
long by 35 to 38 microns wide. 



Fig. 51. Hymenolepis anatina. Egg. Enlarged. From Braun, 1897, after Schmidt. 

The eggs of tapeworms belonging to the family Hymenolepididae 
have several thin, transparent shells or membranes, as a rule. In the 
case of Choanotaenia infundibulum (chicken, turkey; U. S.), the eggs 
(Fig. 50) are oval, with a thin membrane next to the onchosphere, then 
a thick, smooth membrane, and then one or two very thick outer mem¬ 
branes, 60 to 65 microns long by 40 to 45 microns wide, and with a 
delicate appendage at each pole. The eggs of Hymenolepis anatina 



F'ig. 52. Hymenolepis tennirostris. Egg. x 240. From Krabbe, 1869. 

(duck, swan) have the characteristic shape figured here (Fig. 51) and 
are 125 to 175 microns long by 90 microns wide. The eggs of H. tenui- 
rostris (duck, goose) are almost cylindrical and 85 microns long (Fig. 
52). Usually these tapeworm eggs are globular or subglobular to ellip¬ 
tical. The diameters of the eggs are given here in microns for the fol¬ 
lowing species: H. carioca (chicken, turkey; U. S.), 36 to 75; H. exilis 
(chicken), 56 to 65; H. cantaniana (chicken, turkey, peafowl; U. S.), 


51 





45 to 60; H. columbae (pigeon), 36; H. collaris (duck, goose), 42 to 44; 
H. megalops (duck; U. S.), 45 to 57; H. venusta (duck), 47 by 30; 
H. sagitta (duck), 44 by 34; H. setigera (goose), 53 by 28; H. 
fedtschenkowi (chicken), 75 by 50; Drepanidotaenia lanceolata (goose, 



Fig. 53. Drepanidotaenia lanceolata. Egg. x 300. From Stiles, 1896, after Railliet. 

duck), 50 by 35 (Fig. 53); Monopylidium gallinarum (chicken), 35; 
Amoebotaenia sphenoides (chicken; U. S.), 42 (Fig. 54); Metroliasthes 
lucida (turkey, chicken, guinea fowl; U. S.), 75 by 50 (Fig. 55). 



Fig. 54. Amoebotaenia sphenoides. Egg. x 374. From Meggitt, 1914. 

The eggs of tapeworms belonging to the family Davaineidae also 
have thin, transparent shells or membranes and are very similar to 
those of tapeworms belonging to the Hymenolepididae. Those of 
poultry tapeworms are usually globular or subglobular, but sometimes 



Fig. 55. Metroliasthes lucida. Egg. x 758. From Ransom, 1900. 

elliptical. The diameters of the eggs are given here in microns for 
the following species: Davainea proglottina (chicken; U. S.), 35 to 40 
(Fig. 56); D. tetragona, chicken, turkey, guinea fowl; U. S.), 25 to 50 


52 



(Fig. 57); D. friedbergeri (turkey), 34 to 38; D. bothrioplitis (chicken), 
25 to 40; D. echinobothrida (chicken; U. S.), 25 to 50; D. cesticillus 
(chicken, turkey, guinea fowl; U. S.), 36 to 42 (Fig. 58), according to 
some writers, or 65 by 50, according to others; D. microcotyle (duck), 
40; D. vigintivasus (chicken), 55. 

The family Anoplocephalidae is represented by the species Bertiella 
delafondi parasitic in the intestine of the pigeon. The egg (Fig. 59) 
of this worm has 2 thin shells outside of the onchosphere and is 55 to 



Fig. 56. Davainea proglottina. Egg. Enlarged. From Stiles, 1896, after Blanchard. 

65 microns in diameter; the piriform apparatus, noted in a previous 
paper as present in eggs of cattle tapeworms belong to this same fam¬ 
ily, Anoplocephalidae, is not present. 

The family Fimbriariidae is represented by the species Fimbriaria 
fasciolaris, parasitic in the duck and goose. The egg has thin shells 



Fig. 57. Davainea tetragona. Egg. Enlarged. From Lopez Neyra, .1920. 

and is 37 to 45 microns long by 21 to 23 microns wide. 

The eggs of nematodes belonging to the superfamily Spiruroidea 
are usually elliptical and contain embryos when deposited. Most of 
the following species occur in the digestive tract, usually embedded 
more or less in the tissues. Oxyspirura mansoni and O. parvovum 


53 


occur in the eyes, but the eggs pass through the lachrymal ducts and 
are swallowed, escaping in the droppings. Filaria gallinarum is a 
spirurid, not a Filaria, but its description does not permit of its assign¬ 
ment to a genus of spirurids at present. The dimensions of some of 
these spirurid eggs in microns are as follows: Filaria gallinarum 
(chicken), 40 by 24; Oxyspirura mansoni (chicken, turkey, peafowl; 
U. S.), 50 to 65 by 40 to 45 (Fig. 60); O. parvovum (chicken), 33 to 45 



50m, 

Fig. 58. Davainea cesticillus. Egg in capsule. From Lopez Neyra, 1920. 

by 25 to 30; Streptocara pectinifera (chicken, guinea fowl), 33 by 20; 
Gongylonema ingluvicola (chicken; U. S.), 50 by 36; Dispharynx 
spiralis (chicken, guinea fowl, pigeon), 36 to 40 by 19 to 21; Cheilo- 
spirura hamulosa (chicken; U. S.), 30 by 20; Tetrameres fissispina 
(duck, turkey, chicken, pigeon), 50 by 28; T. confusa (chicken, turkey, 
pigeon), 33 by 24; T. gigas (duck) 50 by 21; Physaloptera bulbosa 
(peafowl), 44 by 26. 


54 




The eggs of nematodes belonging to the superfamily Strongyloidea 
are usually thin-shelled and elliptical and are usually segmenting when 
deposited. The dimensions in microns of some of the eggs of worms 



Fig. 59. Bertiella delafondi. Egg. Enlarged. From Johnston, 1918. 

in this superfamily are as follows: Trichostrongylus tenuis (chicken, 
duck, goose; cecum), 66 to 75 by 35 to 42; Ornithostrongylus 
quadriradiatus (pigeon; intestine; U. S.), 70 to 75 by 38 to 40; 



I-1 

50/ia. 

Fig. 60. Oxyspirura mansoni. Eggs. From Ransom, 1904. 

Epomidiostomum orispinum (goose; esophagus and proventriculus), 
95 by 55; E. anatinum (duck; gizzard), 74 to 80 by 48 to 50; Syngamus 
trachealis (chicken, turkey, peafowl; U. S.), 85 to 90 by 50, with 


55 





operculum at each end (Fig. 61); S. bronchialis (goose, duck; larynx, 
trachea and bronchi), 80 to 90 by 60, with an operculum at one end. 
The eggs of Amidostomum anseris (goose, duck; esophagus, proven- 
triculus and gizzard) are 84 microns long by 50 microns wide and 
contain an embryo when deposited. 

The eggs of the worms belonging to the family Heterakidae of 
the superfamily Oxyuroidea are usually thick-shelled and are usually 
not yet segmenting when deposited. The dimensions of some of these 
eggs in microns are as follows: Heterakis papillosa (chicken, turkey, 
guinea fowl, peafowl, duck, goose; ceca; U. S.), 63 to 71 by 38 to 48 



Fig. 61. Syngamus trachealis. Eggs in various stages of development. Enlarged. 

From Neumann, 1909, after Railliet. 

(Fig. 62); Ascaridia perspicillum (chicken, turkey, guinea fowl; 
intestine; U. S.), 75 to 80 by 45 to 50; A. lineata (duck, chicken; 
intestine), 80 by 50; A. columbae (pigeon; intestine; U. S.), 60, 68, 72 
and 80 to 90 microns long, according to various writers, by 40 to 50 
microns wide. A member of the same family, Subulura differens 
(chicken, guinea fowl; intestine), has eggs which are almost spherical, 
59 microns long by 50 microns wide, containing embryos when 
deposited. 

The worms belonging to the superfamily Trichuroidea have lemon¬ 
shaped eggs as a rule. The dimensions in microns of the eggs of 
some of these worms are as follows: Capillaria retusa (chicken, 


56 









guinea fowl; intestine and ceca), 45 to 65 by 18 to 24, or by 28 to 32, 
according to some writers; C. collare (chicken; intestine), 66 by 30; 
C. meleagris (turkey; intestine and ceca), 54 to 56 by 25 to 27; 



o.i mm. 



Fig. 62. Heterakis papillosa. Eggs from uterus. Adapted from Lane, 1918. 

C. contorta (duck; esophagus and crop), 48 to 56 by 21 to 28 (Fig 63); 
C. anatis (goose; intestine and ceca), 42 to 46 by 24 to 25; C. dujardini 



Fig. 63. Capillaria contorta. Eggs, x 300. From Railliet, 1893. 

(pigeon; intestine), 53 to 56 by 28 to 32; C. strumosa (chicken; 
esophagus and trachea), 60 to 66 by 28. 


57 






The eggs of the following nematodes are somewhat oblong and 
truncated and have tuberculated or pitted shells: Hystrichis tricolor 
(duck; esophagus and proventriculus), 85 to 88 by 36 to 40; Eustron- 
gylides elegans (duck; esophagus and proventriculus), 60 to 70 by 
33 to 38 (Fig. 64); E. tubifex (duck; intestine), 65 to 75 by 44; 



Fig. 64. Eustrongylides elegans. Egg. Enlarged. From Jagerskiold, 1909. 


E. papillosus (duck, goose; esophagus), 68 by 36. 

The eggs of the echinorhynchs or thorny-headed worms of birds 
are elliptical and thick-shelled, similar to those previously described 
for such worms from other domesticated animals. Two species of 
echinorhynchs which occur in the intestine of the duck, goose and 



Fig. 65. Filicollis anatis. Egg. x 340. From Luehe, 1911, after Marval. 

swan are Polymorphus minutus, with eggs 91 to 110 microns long by 
26 to 30 microns wide, and Filicollis anatis (Fig. 65), with eggs 56 to 
60 microns long by 26 to 30 microns wide, according to some writers, 
or 62 to 70 microns long by 19 to 23 microns wide. 


58 








Spurious Parasites in the Feces 
of Animals 


SPURIOUS parasite may be defined as anything which is not a 



XA. true parasite, at least in the host in which it is found, but which 
has been regarded as a parasite in that host or which may be mistaken 
for a parasite of that host. 

Some of these spurious parasites are true parasites of hosts other 
than the one in which they are found; thus Oxyuris compar, reported 
by Leidy from the small intestine of the cat, is probably O. ambigua 



Fig. 66. Dark fibre cells of banana, showing arrangement resembling tapeworm 
strobila. Enlarged. From Stiles and Hassall, 1902. 


from the large intestine of the rabbit, the cat having eaten the rabbit 
intestine a short time before the death of the cat and of the finding of 
the worm in the small intestine postmortem. 

A second group of spurious parasites is composed of non-parasitic 
animals which have been eaten and subsequently found in the digestive 
tract or feces of the animal which ate them; thus various insect larvae 


59 




have often been regarded as parasitic, though many such cases deal 
with insects incapable of such parasitism and often found to be dead 



Fig. 67. Seed of Indian mustard, Brassica juncea. Enlarged. From Beal, 1910. 

and partly digested when carefully examined. 

A third group of spurious parasites consists of portions of the host 



Fig. 68. Seed of shepherd’s purse, Bursa bursapastoris. Enlarged. From Beal, 1910. 

structure, such as ciliated tracheal cells which have been regarded 
as causative organisms in whooping cough, or lymphatic glands and 



Fig. 69. Seed of daisy fleabane, Erigeron ramosus. Enlarged. From Beal, 1910. 

pacchionian bodies which have been regarded as hydatids. 

A fourth group of spurious parasites, and one of especial interest 



Fig. 70. Seed of bird’s foot trefoil, Lotus corniculatus. Enlarged. From Beal, 1910. 


in connection with spurious parasites in feces, is composed of plant 
and animal material which may be mistaken for parasites and parasite 

60 


eggs. Plant material is especially likely to be mistaken for parasites 
owing to its greater content of indigestible substances as compared 
with animal material. Aside from bones, which are usually readily 
recognizable, there is comparatively little in the way of animal material 
which passes the digestive tract undigested, but the high content of 
cellulose and related substances in plants furnishes an abundance of 



Fig. 71. Pollen-spore of a pine, Pinus insignis. Enlarged. From Campbell, 1902. 

undigested materials which may simulate parasites, and numerous 
seeds and spores simulate parasite eggs. 

Among the objects commonly present in feces and frequently 
mistaken for parasites are plant hairs. These are usually mistaken for 
nematodes of some sort, the hair being somewhat pointed at its free 
end and sometimes having a structure slightly suggestive of a 
strongyle bursa at the end originally attached. The writer has known 
these hairs to be mistaken for nematodes by a man of several years 



Fig., 72. Cell of yeast fungus, Saccharomyces cerevisiae, containing 4 spores. 
Enlarged. From Campbell, 1902, after Reess. 


experience in the field of parasitology and has called attention to one 
case in which such a plant hair was reported as a trichina larva in 
the blood. The homogeneous structure of these hairs and the lack 
of any internal structures resembling those in nematodes should be 
sufficient to distinguish them from worms. Fibrous connective tissue 
may sometimes be mistaken for nematodes, but here also the lack of 


61 


any internal organization resembling that of nematodes enables one 
to differentiate these structures. Numerous structures belonging to 
the fibro-vascular bundles of plants may simulate nematodes, but the 
presence of a spiral marking throughout or of regularly pitted mark¬ 
ings along a cylindrical structure is suggestive of plant material. In 
case of doubt, always examine the object for the internal structure 
which should be present if it is a nematode. 

Various substances simulate tapeworm segments. One which was 
reported years ago by Stiles and subsequently by various writers, and 
which the writer has seen on several occasions, consists of banana 
fibres (Fig. 66), which may have an arrangement very similar to a 
small tapeworm. Blanchard has noted a case in which a piece of 
peach skin was determined as a fragment of hydatid cyst. 



Fig. 73. Ripe spores of corn smut, Ustilago maydis. x 600. From Campbell, 1902. 


Of the things which may resemble flukes the pulp vesicles of the 
lemon and orange deserve mention. Pulp vesicles of the lemon are 
commonly present in lemonade and may pass intact in the feces of 
persons who have recently drunk lemonade. The superficial re¬ 
semblance of these vesicles to flukes has been mentioned by a number 
of writers, including Leuckart, Stiles and Ransom, in connection 
with cases of mistakes in identification of parasites. The lack of any 
internal structure in any way resembling that of a fluke should be 
sufficient to prevent one from mistaking pulp vesicles for flukes. 
Careful washing to remove fecal matter, mucus, etc., is a great aid in 
determining the true nature of supposed parasites. As a matter of 
fact, such mistakes in identification are usually made as a result of 
total unfamiliarity with parasites or as a result of snap judgment. 


62 


The spurious parasites which are of most practical importance are 
the numerous objects, mostly plant material, which occur in feces and 
which resemble parasite eggs. To differentiate such material several 
tests may be applied. Such spurious parasites are frequently very 
different in size from the eggs which they resemble, and an accurate 
measurement will often show that they are not the eggs they are 
supposed to be. Plant material as a rule is more dense, more often 
colored, and shows less cell structure internally than do parasite eggs. 
Cestode eggs may be definitely determined by the presence of the 
6 hooks of the onchosphere. Fluke eggs usually show an operculum 
or lid at one end. Nematode eggs are very variable in size and shape, 



Fig. 74. Two views of the diatom Pinnularia viridis. Enlarged. From Campbell, 1902. 


but they usually contain an embryo or else cells in process of division, 
and the shell is definitely delimited from the egg content to an extent 
which is not true of the external coat and the content of a plant spore. 
In a general way it is true here as elsewhere that other things may 
look like the thing you are in search of, but the thing itself is un¬ 
mistakable when you find it. A parasite egg is evidently a parasite 
egg; it doesn’t merely look like a parasite egg. Doubtful eggs are 
usually to be regarded as not eggs. As a final test of the matter one 
may sometimes use chemical reagents to differentiate plant material 
from animal material. The addition of tincture of iodin to a slide will 
color starches blue. By adding sulphuric acid and iodin cellulose sub- 













stances will be colored violet or black, and nematode eggs will be 
colored black with a light areole where the shell shows at the peri¬ 
phery. Various stains have been used to stain plant material and 
leave worm eggs standing out against a stained background. Among 



Fig. 75. A diatom, Navicula sp. x 500. From Campbell, 1902. 


these stains are magenta, used by Giles, methyl green, used by Looss, 
Orange-G, used by Taylor, and gentian violet, used by Fauntleroy and 
Hayden. It is rarely necessary to resort to such elaborate technic to 
determine whether material is parasitic if one has been properly in- 



Fig. 76. A pelagic diatom, Planktoniella sol, viewed from above, x 125. From 
Campbell, 1902, after Schuett. This is actually disk-shaped. 


structed in the subject of making fecal examinations, but when one 
must learn the art unaided, such devices are sometimes of value. 

There should be little occasion to confuse the seeds of the higher 
plants with parasite eggs, as the seeds are usually much larger and 
are densely opaque. A distinctive structure of seeds is the micropyle, 
the aperture at which the young plant starts to grow from the seed. 
However, such confusion does arise and the Veterinary Record for 
October 3, 1914, reports a case in which small brownish objects in the 
feces of a patient were regarded as parasite eggs and subsequently 
found to be vanilla seeds, the patient being accustomed to drinking a 


64 





certain brand of cocoa which was found to contain such seeds. Straw¬ 
berry seeds are frequently mistaken for parasitic material. As illustra¬ 
tions of the superficial resemblance between seeds and parasite eggs, 
there are figured here, the seeds of Indian mustard (Fig. 67), super¬ 
ficially resembling an ascarid egg of some sort; the seed of shepherd’s 
purse (Fig. 68), which if cleared to show this structure might resemble 



Fig. 77. A division stage in a gonidium of one of the green algae, Pleodorina 
californica. Enlarged. From Campbell, 1902, after Shaw. 


an echinorhynch egg or a nematode egg; the seed of the daisy fleabane 
(Fig. 69), which in outline is very similar to a whipworm egg; and the 
seeds of the bird’s foot trefoil (Fig. 70), to show the mfcropyle char¬ 
acteristic of seeds. 

A related body which is often found in feces in the spring is the 



Fig. 78. A unicellular plant, Chlorococcum sp., the one on the right showing 
division, x ca. 1000. From Campbell, 1902. 


pollen-spore of the pines, this pollen being distributed in clouds 
on a windy day and occurring over wide areas about pines. The 
pollen-spore (Fig. 71), has a 3-part structure, consisting of a central 
body and 2 wings, and is practically unmistakable. 

Various fungi produce cells or spores which call for some con¬ 
sideration as to identity the first time one sees them in feces. As 


65 


illustrations there are figured here a cell of the yeast fungus (Fig. 72) 
and some ripe spores of the corn-smut (Fig. 73). 

Unicellular plants, belonging to the large group of algae, are 
frequently found in feces owing to their occurrence in water supplies 
of domestic animals. Some of these are figured here. Two of the 
diatoms figured (Figs. 74 and 75) have somewhat the outline of whip¬ 
worm eggs, but have a quite different internal organization and have 



Fig. 79. One of the Schizophyceae, or blue-green algae, Chroococcus turgidus, show¬ 
ing 4 cells surrounded by a gelatinous envelope, x 500. From Campbell, 1902. 


the distinct and delicate striation which is characteristic of the diatoms; 
the other diatom (Fig. 76) has a slight resemblance to the well known 
figures of the bothriocephalid tapeworm egg, but this diatom is flat, 
whereas the tapeworm egg is almost spherical. Various cells of algae 
are figured as figures No. 77, 78, and 79 to show the superficial re¬ 
semblance of these cells to parasite eggs. The presence of chlorophyll 
in most of the algae is sufficient to distinguish them from parasite eggs. 

Among the confusing objects which may be mistaken for worm 
eggs are the eggs of parasitic or free-living mites. They are especially 
likely to occur in the feces of mangy animals. These eggs (Fig. 16) 
are usually larger than most worm eggs. 


66 





Anthelmintic Medication for 
Worms Outside of the Digestive 

Tract 


T HE term anthelmintic is usually applied to drugs intended to 
destroy worms in the lumen of the digestive tract, but it may 
also be applied to drugs intended to destroy worms in the 
lumen of other organs, such as the air passages of the lungs, or to 
worms in various tissues, including the blood, or in cavities, such as 
the peritoneal cavity. This latter group of anthelmintics has been 
discussed in a paper by Ransom and Hall (1912). As yet we have 
but few drugs of value against worms situated outside of the lumen 
of the digestive tract, and but few worms are as yet known to be 
susceptible to successful attack by these drugs. 

The cases in which worms not in the lumen of the digestive 
tract are amenable to anthelmintic treatment may be briefly sum¬ 
marized as follows: 

LIVER FLUKE MEDICATION 

The liver fluke of sheep may be successfully removed by means 
of male fern and its derivatives and to a lesser extent by kamala 
and its derivatives. The male fern treatment, which has received 
recognition in practice in Europe only during the last few years, was 
first proposed by Grassi and Calandruccio (1884; 1885) almost 40 
years ago. It was favorably reported on by Perroncito (1885; 1886), 
all of these Italian authorities detailing experiments which showed 
the value of the treatment in killing flukes! Over 20 years later, 
another Italian, Alessandrini (1908), reported experiments showing 
that male fern would kill flukes, and 3 years later Borini (1911) 
reported success with this drug against the liver fluke in sheep and 


67 


cattle. This same year, French investigators, Railliet, Moussu and 
Henry (1911), confirmed the finding of the Italian investigators. Fol¬ 
lowing this, male fern derivatives were marketed as proprietary reme¬ 
dies by French, German and Hungarian firms. Floris (1907; 1908) 
reported that carbon bisulphid is effective in removing Fasciola hep- 
atica, but no one appears to have investigated his claims. Marek 
(1916) came to the conclusion that kamala was more effective in 
destroying liver flukes than was male fern, but later (Marek, 1917) 
he concluded on the basis of further experiments that the best treat¬ 
ment for liver flukes was by means of the administration of male 
fern derivatives in lipoid solution. Such a lipoid-soluble preparation 
is now being marketed in Europe. The efficacy of male fern and 
kamala against Fasciola hepatica evidently depends on the blood¬ 
sucking habit of the fluke, as the lancet fluke, Dicrocoelium dendriti- 
cum, which also occurs in the bile ducts, but is not a blood-sucker, 
is not affected by these drugs. According to Marek (1916), the 
active phloroglucin derivatives of male fern and kamala are absorbed 
in the intestine and carried to the liver in the portal circulation, and 
are there taken in by the liver flukes as they feed on blood. 

BLOOD FLUKES IN MAN 

The human blood flukes, more especially Schistosoma haemato¬ 
bium, but apparently S. japonicum and S. mansoni also, may be de¬ 
stroyed by anthelmintic treatment. According to Cawston (1921), 
S. bovis may be destroyed in the same manner. Joannides (1911) 
reported injections of salvarsan as curative in 8 cases, but Conor 
(1911), Fuelleborn and Werner (1912), and Day and Richards (1912) 
have been unable to confirm his findings. Diamantis (1917; 1918) 
found emetine of value in destroying blood flukes, and though his 
findings were not substantiated by Morel and Maldonado (1918), 
they have since been substantiated by the work of Mayer (1918), 
Erian (1918), Balfour (1920), Day (1921), Tsykalas (1921) and others 
in thousands of cases. This drug, emetine, has been given intra¬ 
venously, subcutaneously and intramuscularly in the treatment of 


68 


venal distomiasis. Christopherson (1918) proposed the use of tartar 
emetic intravenously for the treatment of this disease, this drug 
having been used previously in intravenous injections for the treat¬ 
ment of rats infested with the trypanosomes of nagana and surra by 
Plimmer and Thompson (1907), of sleeping sickness by Broden and 
Rodhain (1908), for American leishmaniasis by Vianna and Machade 
(1913), and for Mediterranean and Indian leishmaniasis by other 
workers subsequently. Christopherson’s findings in regard to the 
value of the treatment in venal distomiasis were confirmed by the 
findings of McDonagh (1918), Wiley (1918), Low (1920), Cawston 
(1920-1921), Christopherson and Newlove (1921), Day (1921), Las- 
brey and Coleman (1921) and others. Cawston (1921) finds that both 
emetine and tartar emetic are effective against Schistosoma haema¬ 
tobium S. mansoni and S. bovis. Day (1920) believes that emetine 
is indicated in preference to tartar emetic for small children, per¬ 
sons with veins too small to inject readily, persons intolerant of 
tartar emetic, those in whom an error of technic has resulted in 
abscess formation and in cases complicated by amebiasis. He also 
finds colloidal antimony effective and to be preferred to tartar 
emetic for treating children. Cawston (1921) prefers emetine to tar¬ 
tar emetic for children and young persons. Recently, Wilson (1922) 
has reported favorably on the rectal administration of tartar emetic, 
a method which saves time, is free from risk, and causes less nausea 
and vomiting. The drug is absorbed by the veins of the intestine, 
thereby coming in contact with the worms in the blood. 

VALUE OF MEDICATION NOT KNOWN 

Little is known as yet with regard to the value of anthelmintics 
against other flukes outside of the lumen of the digestive tract. Ac¬ 
cording to a review, Ando (1918) has had good results in the treat¬ 
ment of infestations with the lung fluke, Paragonimus westermani, 
by means of tartar emetic, but no details of these studies are avail¬ 
able to us. Low (1920), believes that this drug will be of value 
against P. westermani, Clonorchis and other flukes, but evidence in 
regard to such efficacy appears to be lacking as yet. It may be sur- 


69 


mised that where flukes lie in the blood, as do the blood flukes, or 
feed on blood, as does Fasciola hepatica, anthelmintic treatments for 
their destruction will probably be developed, but that flukes which 
are encysted, as P. westermani or Agamodistomum suis, or which 
do not feed on blood, as Dicrocoelium dendriticum, will be distinctly 
more difficult to destroy by anthelmintic treatment, though the possi¬ 
bility of accomplishing their destruction in this way is by no means 
out of the question. D. dentriticum might be amenable to anthel¬ 
mintics eliminated in the bile. 

CESTODE MEDICATION 

In the case of cestodes outside of the lumen of the digestive 
tract, little has been accomplished as yet in the way of anthelmintic 
treatment. For the most part, such cestodes are larvae encysted in 
tissues, and while the growth of these larvae shows that they absorb 
solid and fluid material from their host, the growth is slow and it is 
evident that the absorption is very slow, a feature which promises 
little for the success of anthelmintic treatment. Ziirn (1882) was 
unable to find a drug that would destroy the gid parasite in the 
brain of sheep in the course of 24 years’ experiments along this 
line. Hall (1909) and Moussu (1910) found repeated doses of male 
fern ineffective in gid in sheep, the parasites being found alive after 
the conclusion of the treatment. Feletti (1894), de Renzi (1908) and 
Dianoux (1909) have reported cures of a total of 6 cases of cysticer- 
cosis in man following repeated doses of male fern. Moussu (1910) 
was unable to cure a similar case of cysticercosis in a pig by this 
treatment. De Renzi (1908) reported the cure of 2 cases of hydatid 
disease in man by the administration of repeated doses of male fern, 
but Deve (1911) was unable to obtain similar results in cases of 
hydatid infestation in rabbits. Deve and Payenneville (1914) found 
repeated injections of neosalvarsan intravenously of no value in pre¬ 
venting the development of hydatids in rabbits. Recently, Deve and 
Payenneville (£922) have reported the same negative results with 
novarsenobenzol. 


70 


Of the adult cestodes occurring outside of the lumen of the 
digestive tract, we find such forms as Thysanosoma actinioides in 
the bile ducts. Curtice (1889; 1890) was unable to find a satisfactory 
treatment for these worms in tests with pumpkin seed, pomegranate- 
root bark, koosoo, kamala, male fern, and worm seed. Stiles (1902) 
found arsenic of no value against fringed tapeworm. Ransom and 
Hall (1912) were unable to destroy these fringed tapeworms by 
means of repeated doses of carbon bisulphid or of male fern. 

The findings in many of the cases dealing with the treatment of 
intestinal and of somatic taeniasis are somewhat vague or uncertain 
and it is necessary to reserve judgment in these cases as regards the 
efficacy or inefficacy of the treatment. Undeniably the results ob¬ 
tained in attempts at treatment to destroy tapeworms outside of the 
lumen of the digestive tract are inferior to those obtained in the case 
of certain flukes. Probably these tapeworms are less susceptible to 
anthelmintic treatment than are the flukes in question, but more 
work is necessary along this line. 

NEMATODE MEDICATION 

The nematodes outside of the lumen of the digestive tract, like 
cestodes so situated, are less amenable to anthelmintic treatment than 
are the trematodes. The reason for their resistance does not appear 
to be the same as in the case of cestodes. Many of these nem¬ 
atodes are not encysted and some of them must feed on blood or 
lymph. While the nematode cuticle may be thought to be more re¬ 
sistant than the corresponding structure in flukes or tapeworms, it 
must be borne in mind that certain drugs will destroy nematodes in 
the lumen of the digestive tract in cases where the same drugs 
entirely fail to show any adverse effect on flukes or tapeworms 
similarly situated. The reverse of this is, of course, true. It ap¬ 
pears, therefore, that we must consider the action of anthelmintics 
as more or less specific and that the question of penetration is of 
little moment, whereas the finding of a suitable drug is of prime im¬ 
portance. In a general way it may be said that other things being 


equal it is no more difficult to remove or destroy one kind of worm 
than to remove or destroy any other kind. With a suitable drug the 
removal or destruction is easy; without such a drug it is difficult or 
impossible. The present literature on the treatment of infestations 
with nematodes outside of the lumen of the digestive tract has little 
in the way of definite positive results to record as yet and can only 
be briefly summarized here. 

TREATMENT OF TRICHINOSIS 

In the treatment of trichinosis, recommendations of various drugs 
have been made largely on the basis of clinical improvement or cure, 
without reference to whether the worms present in the muscles were 
affected or not affected by the drug. On such a basis McNerthney 
thymol of value when given subcutaneously or intramuscularly In re¬ 
peated doses, and Rosique (1917) found grey oil of value. But 
Eisenhardt (1918) found that thymol did not prevent the development 
of trichinae, and Romanovitch (1912) found salvarsan devoid of action. 
In trichinosis there are several factors present, and a given treatment 
may leave the larval worms in the tissues unaffected and at the same 
time aid the patient by the elimination of adult worms from the lumen 
of the intestine, by neutralizing toxins, etc. As an illustration it may 
be noted that Salzer (1916) found the use of serum from recovered 
patients valuable in the treatment of other patients and claimed that 
the use of such a serum in animals would prevent the development 
of trichinosis. Schwartz (1917) tested these claims and found that 
trichinae would develop in animals regardless of the use of serum. 
Hall and Wigdor (1918) also carried out tests along this line and 
although they confirmed Schwartz’s findings to the effect that 
trichinae would develop in spite of the use of serum, they found that 
treated animals usually lived longer than untreated animals. They 
concluded that the serum of animals which had recovered from trich¬ 
inosis probably had anti-bodies which were of service in neutralizing 
certain worm toxins responsible for part of the pathological conditions. 
Von Linden (1917) claims that severe trichinosis can be prevented in 
guinea pigs and rabbits by feeding them copper preparations, check 


animals becoming heavily infested. This claim requires confirmation. 
At the present time we know of no drug that has been definitely ascer¬ 
tained to kill trichinae in the muscles. 


TREATMENT OF FILARIDS 

Aside from trichinae, the worms which have received the most 
attention from the standpoint of medicinal treatment are the filarids. 
The papers on this subject do not indicate that much of a definite 
and positive nature has yet been established. Schultz has reported 
success in killing the adult Loa loa in the connective tissue of man, 
together with the larvae in the blood, by the administration of a 1 
per cent solution of collargol in dessertspoonful doses three times a 
day for over a year. Thiroux and d’Anfreville (1910) report the 
disappearance of L. loa in a patient treated with aniline tartrate. 
Morlot and Zuber (1914) report the disappearance of this worm fol¬ 
lowing injections of neosalvarsan. Rogers (1919) and Das (1920) 
have reported favorably on tartar emetic in infestations with Filaria 
bancrofti, but Low and Gregg (1920), Macfie (1920) and Low and 
O Driscoll (1921) report unfavorably on this drug, Macfie’s cases in¬ 
cluding infestations with F. bancrofti, F. perstans and L. loa. Low 
and O’Driscoll found emetine also ineffective, and though Miihlens 
(1921) has seen filariae disappear from the blood after emetine, he 
regards this as spontaneous or accidental, another case showing no 
results after emetine, tartar emetic and neosalvarsan. Siebert (1920) 
found that filariae disappeared in the case of an undetermined species 
of filarid after treatment with picric acid and refers to Scheube (1910) 
as having seen the microfilariae of F. bancrofti die in the blood after 
the administration of potassium picrate. Ikegami (1920) reported 
that after 2 injections of arsaminol (Japanese salvarsan) in the case 
of one patient, the microfilariae disappeared from the blood and the 
urine became clear; no chyluria or other symptoms reappeared in 
over a year. Curasson (1920) reports that he treated 3 carrion 


73 


crows of Senegal, all harboring microfilariae in the blood, with in¬ 
jections of galyl. The microfilariae disappeared from one bird for 9 
days and then reappeared; no adult worms were found postmortem. 
The microfilariae became rare and less active in the second bird; 
2 adult worms were found dead in the abdomen postmortem. No 
microfilariae were found in the third bird for 12 days; 1 worm, 
aparently dead, was found in the abdomen postmortem. Macfie 
(1920) treated 23 patients infested with Guinea worm, Dracunculus 
medinensis, by means of intravenous injections of tartar emetic; the 
worms and embryos died and could either be extracted safely or 
allowed to become absorbed. Jeanselme (1919) Montpelier and 
Ardoin (1919), and Grey (1920) report similar good results in 
infestation with Guinea worm from the use of injections of novar- 
senobenzol. 

The foregoing indicates that as yet we lack adequate evidence 
establishing any drug as effective in the treatment of cases of infesta¬ 
tion with Filaria bancrofti; that we may have a satisfactory treat¬ 
ment for Loa loa, though more work must be done to establish this; 
and that we apparently have satisfactory treatments for Dracunculus 
medinensis. 

In a paper read before the last meeting of the American Veter¬ 
inary ' Medical Association, Hall and Shillinger reported some tests 
of intravenous injections of carbon tetrachlorid and of tartar emetic 
for the destruction of Strongylus vulgaris in aneurisms in horses 
While these tests were inconclusive, the finding of a dead worm in 
an aneurism in one case suggests that further work along this line 
might result in the development of a satisfactory treatment for the 
destruction of these worms. 

We have as yet no well established treatment for lungworms, in 
spite of the many treatments reported in the literature, and at the 
present time nursing treatment, isolation of sick animals, and the pro¬ 
vision of safe and proper food and water supplies are apparently the 
best lines of treatment. 


74 


Anthelmintic Medication for Parasites in the 
Lumen of the Digestive Tract 

In a previous paper the writer has summarized, in a general way, 
our knowledge of anthelmintics for the control of worms outside of 
the lumen of the digestive tract of man and animals, the definite 
knowledge on that subject in the fields of human and veterinary 
medicine not making a total too large for brief consideration in one 
article. In this paper the subject of drugs for the removal of parasites 
from the lumen of the digestive tract will be considered, primarily 
with reference to their use among domesticated animals, with little 
consideration of the rather large subject of anthelmintics used in 
human medicine to remove parasites from the lumen of the digestive 
tract. 

We have at the present time quite satisfactory treatments for the 
removal of many of the common parasites of the digestive tract, the 
treatments in some cases being established by critical tests and the 
tests subsequently supported by clinical experience, and in other cases 
being established by clinical experience and clinical experience subse¬ 
quently supported by critical tests. On the other hand, there are a 
number of parasites for which we have as yet no satisfactory treat¬ 
ment, notably the spirurids living partly in the lining and partly in the 
lumen of the digestive tract, and the tapeworms of birds. 

FASTING 

In administering anthelmintics by mouth, it is customary to fast 
the animals to be treated in order to diminish the amount of ingesta 
in the digestive tract, this ingesta acting as a diluent for the anthelmin¬ 
tic and also affording mechanical protection to worms in some instances. 
The length of the preliminary fast varies with the nature of the host 
animal and the location of the worm. A fast of 18 hours has been 


found to be adequate as a preliminary to treating horses for bots, 
but it seems necessary to fast a horse 36 hours in order to obtain 
satisfactory results in treating to remove strongyles from the large 
intestine. The directions given in regard to fasting should, therefore, 
be observed. Additional information is needed in some cases as to 
the length of the fast to be observed, but the directions are as accurate 
as it is possible to make them in the present state of our knowledge 
and in many cases a different fasting period, especially a shorter one, 
is known to give inferior results. Animals may be watered soon after 
treatment, but should not be fed for two to three hours, as feeding 
immediately after treatment defeats the purpose of the preliminary 
fasting. 


MASS TREATMENTS VERSUS INDIVIDUAL TREATMENTS 

There is always a demand for mass treatments where large num¬ 
bers of animals are to be treated, and this demand is not limited to the 
farmer but includes some veterinarians. It is a very natural demand, 
since the individual treatment of large numbers of animals, especially 
those where the value of the individual animal, such as a chicken, is 
low by comparison with the larger domesticated animals, requires a 
disproportionately large amount of time in the aggregate. The farmer 
feels that the benefits derived from a treatment of this sort in such 
cases do not compensate for the expense incurred in paying a veterin¬ 
arian for such treatments—and in some cases this would be true. 
For practical purposes, therefore, we may use mass treatments where a 
certain degree of benefit may be expected and where individual treat¬ 
ments, which would be more beneficial, cannot be used owing to the 
time and cost factors. 

Mass treatments are usually in the nature of treatments by means 
of substances added to the feed. Animals are usually fasted before 
such treatments, but the fasting is not for the purpose of emptying the 
digestive tract, as a rule, so much as to make the animals hungry enough 


76 


to eat food to which some more or less unpalatable anthelmintic has 
been added. The presence of the food distinctly diminishes the efficacy 
of the anthelmintics, but there is usually some anthelmintic action with 
suitable drugs and as the food dilutes the anthelmintic and in this 
way, as well as mechanically, probably protects the mucosa of the 
digestive tract against irritant action and retards absorption to some 
extent, somewhat larger doses of the drug may be tolerated than 
would be tolerated by a fasting animal which was not given feed with 
the drug. On the other hand, it must be remembered that where a 
drug is mixed with the feed for a number of animals, some animals 
will eat more than others, and perhaps get more of the drug than can 
be well tolerated, whereas other animals will find the drug too distaste¬ 
ful and will get too little to be of value. The animals which eat little 
or none of the medicated feed may be the ones which are most in 
need of treatment. Mass treatments are most used in the case of 
poultry, the animals having the smallest value per head and the ones 
which are kept in the largest numbers as a rule. Chickens and swine 
are probably the most difficult to catch of the domesticated animals, 
and swine are probably the most difficult to treat, these things account¬ 
ing in part for the demand for mass treatments for these animals. 


COMPLICATIONS DUE TO LARVAL WORMS PRESENT 

In a paper on the treatment of horses for the removal of 
worms the writer has called attention to the fact that there are many 
cases in which worms, especially certain nematodes, migrate through 
the body of the host or develop in certain tissues for days, weeks or 
months, and that although anthelmintics may remove all of the adult 
worms present at the time of treatment, these larval or agamic worms 
may enter the lumen of the digestive tract soon after treatment and be 
found there, sometimes, in the case of horse strongyles for example, 
as mature worms very soon after treatment. At present the only 
action that can be taken in this connection is to repeat treatment at 


77 


such intervals as the life history of the worms indicates as appropriate, 
or as the clinical condition of the animal calls for it, or as the recur¬ 
rence of eggs in the feces shows the recurrence of infestation. 

PERIODS DURING WHICH WORMS ARE PASSED 

The impression is quite prevalent that almost all worms passed after 
an anthelmintic come away in the first 24 hours after treatment. This 
is not the case. They commonly come away for two or three days, 
and bots may pass for over 17 days after treatment. It is therefore 
unsafe to conclude that a treatment is a failure because worms did not 
come away during the first day after treatment. In the treatments 
given in this paper there is a statement as to the length of time worms 
have been observed to pass after treatment wherever such information 
is available. It is quite probable that worms come away under some 
circumstances for even longer periods than those given. 

EXAMINATION OF FECES FOR WORMS PASSED 

Worms embedded in a fecal mass are easily overlooked, especially 
by persons unfamiliar with worms. The careful veterinarian will dis¬ 
regard the statement of the farmer, stable hand or dog owner who 
assures him that no worms were passed after treatment. A glance 
at the feces or a casual poke with a stick or straw cannot be depended 
on to give accurate information. The most satisfactory method of 
examination is to screen the feces through a screen of suitable size 
to retain the worms, washing as much fecal matter as possible through 
the screens, and then examining the screen. If this cannot be done, the 
feces should be thoroughly picked apart in a good light and carefully 
examined. 


TREATMENTS FOR HORSE PARASITES 

Bets: Fast 18 hours. For a 1000-pound horse, carbon bisulphid 
in capsules; 1 dose of 22 cc. (6 fluid drams); or 2 doses of 15 cc. (4 
fluid drams) each with a two-hour interval between doses; or 3 doses of 
11 cc. (3 fluid drams) each with an hour interval between doses. No 


78 


purgation; oil immediately following treatment especially contrain¬ 
dicated. Bots pass for over 17 days. Efficacy, approximately 100 per 
cent. Carbon tetrachlorid in 25 to 50 cc. doses is approximately 25 per 
cent effective in removing bots. Other drugs are ineffective. 

Ascarids: The same treatment as for bots. Oil immediately fol¬ 
lowing treatment contraindicated. Worms may pass for several days. 
Efficacy approximately 100 per cent for carbon bisulphid and appar¬ 
ently the same for carbon tetrachlorid. 

Palisade worms (Strongylus spp.) : Fast 36 hours. Oil of cheno- 
podium, 16 to 20 cc. (4 to 5.3 fluid drams) in capsule, followed imme¬ 
diately by one liter (approximately one quart) of raw linseed oil 
or by aloes ball. Worms may pass for six days or more. Efficacy, 
95 to 100 per cent. 

Another treatment: Fast 36 hours. Oil of turpentine, 64 cc. (two 
fluid ounces), in capsule, followed immediately by a liter of raw 
linseed oil or aloes ball. Efficacy (ascertained on one animal only), 
approximately 50 per cent. 

Another treatment: Carbon tetrachlorid, 25 to 50 cc. (6.5 to 13 
fluid drams), in capsule. No purgation. Efficacy, 100 per cent. 

Cylicostomes: The same treatment as for palisade worms. Worms 
pass for six to twelve days. Efficacy, approximately 100 per cent for 
chenopodium and oil of turpentine; variable for carbon tetrachlorid— 
from 100 per cent to less than 50 per cent. 

Pinworms: Oil of chenopodium or turpentine as for palisade 
worms. Worms pass for two days. Efficacy, 100 per cent. 

Stomach worms (Habronema spp): Uncertain. It is probable 
that carbon bisulphid, carbon tetrachlorid, oil of chenopodium, and 
possibly turpentine and other drugs will kill the worms in the lumen 
of the stomach, but it is difficult to obtain evidence on this subject 
as worms killed in the stomach are probably digested as a rule. The 
worms embedded in the mucosa or buried under mucus appear to be 
adequately protected against the action of these and other known 

79 


anthelmintics. It has been found by Hodgkins that numbers of these 
worms may be washed out of the stomach by gastric lavage with the 
stomach tube. Possibly anthelmintics could be effectively administered 
in this way. In some cases repeated treatments by mouth or by 
lavage might remove all or practically all of the worms present. 

To clean out the bots and nematode parasites as completely as 
possible from the digestive tract of the horse, give the carbon bi- 
sulphid treatment for bots and ascarids and two weeks later give 
the chenopodium treatment for palisade worms, cylicostomes and 
pinworms. Both drugs will probably kill stomach worms not pro¬ 
tected by mucus or in the mucosa. 

Tapeworms: The presence of tapeworms in the horse is usually 
ascertained postmortem and practically nothing is known in regard 
to treatment. As the worms occur in the stomach, small intestine 
and large intestine, it would require critical tests, which have not yet 
been made, to determine the efficacy of drugs against these worms 
with any degree of accuracy. The indicated drugs for test are those 
in common use against tapeworms, such as oleoresin of male fern, 
kamala, etc. 

TREATMENTS FOR CATTLE PARASITES 

Ascarids: Treatment uncertain as we lack the findings of critical 
tests of anthelmintics for removing these worms. Hornby finds tur¬ 
pentine in doses of two to four fluid drams in a mixture of two fluid 
ounces of linseed and castor oils effective when this dose is given on 
each of two successive morning to calves and a third dose is given a 
week later. A single dose of two drams is ineffective and one ounce 
is too toxic. 

Stomach worms (Haemonchus contortus): The copper sulphate 
solution and the tobacco and copper sulphate solution noted below in 
connection with stomach worms of sheep are probably of some value 
in controlling stomach worms in cattle when given in appropriate doses. 
100 to 300 cc., but in the absence of critical tests we cannot make very 
positive statements in regard to this. Carbon tetrachlorid in doses 
of 100 cc. to calves weighing 80 and 114 kilos (175 and 250 pounds) re¬ 
moved all the stomach worms, but had a toxic effect on the animals, 
the smaller one being dead the fourth day. Adult cattle have suc¬ 
cumbed to doses of 22 cc., but good clinical results are reported from 
doses of 32 cc. (one fluid ounce) of carbon tetrachlorid in one pint of 


80 


olive oil for animals weighing 700 to 800 pounds, and in doses of half 
this amount of carbon tetrachlorid and olive oil for yearlings. At 
present we have too little evidence and experience on which to make 
recommendations. 

Hookworms: The solution of copper sulphate and tobacco dis¬ 
cussed in connection with stomach worms in sheep has been reported 
as effective against hookworms in sheep and might be effective 
against hookworms in cattle, especially in repeated doses. Carbon 
tetrachlorid, in the tests on calves referred to above, removed almost 
half of the hookworms from one calf and 99 per cent of those present 
in the other, each calf having hundreds of worms. As noted, the doses 
given were apparently too large and this subject requires more investi¬ 
gation. Marek has reported satisfactory results from the use of a 
proprietary composed of lipoid-soluble constituents of male fern. 

Nodular worms: Csontos and Pataki report good clinical results 
from the use of the proprietary remedy referred to above as used by 
Marek against hookworms. Carbon tetrachlorid, in the tests of calves 
referred to above removed all the nodular worms from both animals. 
It is not yet known what dose will maintain this efficacy and at the 
same time be safe for cattle; the dose given above was too large for 
safety. 

Small trichostrongyles: Nothing is yet known in regard to the 
removal of these worms from cattle, but carbon tetrachlorid has been 
found more effective against similar worms in sheep than any other 
drug yet tested and might prove effective here in suitable doses. 

Tapeworms: The solution of copper sulphate and tobacco dis¬ 
cussed under the heading of stomach worms of sheep is said to be 
very effective against tapeworms in sheep. In doses suitable for cattle, 
perhaps 100 to 300 cc., this treatment might also be effective against 
tapeworms in cattle. 


81 


TREATMENTS FOR SHEEP AND GOAT PARASITES 


Stomach worms: Copper sulphate, one per cent solution in water, 
to animals fasted overnight; if used as a routine repeated treatment, 
animals need not be fasted. For sheep, 100 cc. (3.5 fluid ounces), for 
lambs, 50 cc. (1.75 fluid ounces.) No purgation. Worms pass for four 
days. Efficacy, 93 per cent as indicated on the basis of worms passed 
and worms present postmortem. As noted in connection with stomach 
worms in horses, many of the worms killed by anthelmintics in the 
stomach are digested there, and the check animals in stomach worm 
experiments on sheep indicate that many of the worms which are 
killed are digested and therefore not accounted for in the examination 
for worms passed; it seems certain that the copper sulphate treatment 
is much more than 93 per cent effective. It falls short of 100 per cent 
efficacy, but is probably close to 99 per cent effective. The doses 
which are given here may be repeated at intervals of three to four 
weeks throughout the year in places where stomach worms are prev¬ 
alent, with decided benefits in the way of increased production of 
mutton and wool. The one per cent solution may be made up at the 
rate of one gram of powdered blue crystals of copper sulphate to 99 
cc. of water, or, for large amounts, at the rate of one-fourth pound of 
copper sulphate dissolved in one pint of boiling water, with cold water 
added to this solution to make a total of three gallons, enough to dose 
100 adult sheep and allow 10 per cent for waste. 

Another treatment consists in using a solution containing one per 
cent copper sulphate solution and one per cent by weight of snuff or 
powdered tobacco. The tobacco is steeped in the water overnight 
and the copper sulphate then added. The dose and method of treat¬ 
ment is the same as for the copper sulphate treatment given above. 
The reported efficacy is 90 to 100 per cent; 90 is probably too low as 
noted above. See Addendum, page 92. 


82 


Carbon tetrachlorid in doses of 12 to 48 cc. in 60 cc. of castor oil 
has been found to remove all the stomach worms from infested sheep. 
The dose which is most satisfactory from the standpoint of efficacy 
and safety has not yet been ascertained. 

A treatment reported favorably from South Africa consists in 
the use of a mixture of sodium arsenite (testing 80 per cent arsenious 
oxid), one part, and copper sulphate, four parts. Doses: Animals two 
to four months old, 0.18 gm.; four to six months, 0.25 gm.; six to 
ten months, 0.375 gm.; one year old, 0.5 gm.; two years old or older, 
0.625 gm. This is given as a powder. Withhold food and water the 
afternoon before dosing; dose next morning; feed in afternoon; feed 
and water the next morning. Treatment may be repeated the day 
after the first dose, allowing feed the afternoon after the first dose, 
dosing the next morning, and feeding that afternoon, but allowing no 
water until the morning following the second treatment. 

Hookworms: The solution of copper sulphate and tobacco admin¬ 
istered in the same dose and manner as for stomach worms. Efficacy, 
on the basis of reported experiments (Guberlet), 100 per cent. 

Carbon tetrachlorid in doses of 15 to 30 cc. in castor oil and in doses 
of four and eight cc. in capsules removed all the hookworms from four 
infested sheep. Worms pass for two days. Further investigations are 
necessary to ascertain the minimum effective dose and the best mode 
of administration. 

Oil of chenopodium, one fluid dram (3.75 cc.) in five ounces 
(160 cc.) of milk has been found to remove about two-thirds of the 
hookworms from sheep. Worms pass for two days. 

Nodular worms: No well established treatment. Carbon tetra¬ 
chlorid in doses of 15 to 48 cc. removed from 3 to 100 per cent of the 
worms present. Further investigation necessary. Larval worms in 
nodules probably not amenable to any known treatments. 

83 


Small trichostrongyles (Nematodirus, Cooperia, Ostertagia and 
Trichostrongylus): Carbon tetrachlorid in doses of 12 to 48 cc. re¬ 
moved 82 per cent of these worms from four infested sheep. From two 
other sheep it removed 3 to 27 per cent. From two other sheep 
doses of 4 to 12 cc. apparently failed to remove any trichostrongyles 
of the genera named. This is the only drug yet reported as capable 
of removing these worms, but further investigations are necessary 
to determine the best dose and mode of administration. The drug 
seems especially effective against species of Nematodirus, these being 
blood-sucking forms and distinctly pathogenic. 

Tapeworms: Copper sulphate and tobacco solution as for stomach 
worms. Efficacy, usually 100 per cent. Copper sulphate solution alone 
will remove some tapeworms. 

Sodium arsenite and copper sulphate as for stomach worms. 

Treatments which have been said to be effective, but concerning 
which we have no evidence from critical tests are: Kamala, one dram 
to lambs; kousso, two drams to lambs; koussin, two grain doses; oleo- 
resin of male fern, one dram with two to four fluid ounces of castor 
oil; areca nut, freshly ground, one to three drams to lambs. 

TREATMENTS FOR SWINE PARASITES 

Ascarids: Fast 24, preferably 36, hours. Oil of chenopodium, one 
fluid dram (3.75 cc.) in or immediately preceded or followed by two 
fluid ounces (ca. 64 cc.) of castor oil for animals weighing 100 pounds 
(45 kilos). Diminish dose of chenopodium for small animals in pro¬ 
portion to weight, but use at least one ounce of castor oil; for larger 
animals the dose of castor oil should be increased, up to four ounces 
for very large animals. Chenopodium requires adequate purgation 
to offset its constipating and toxic action. In default of castor oil, 
which is bulky, it has been suggested that salts be given in soft 
feed of some sort three hours after treatment; no reports on the results 


84 


of such treatments are available. Worms pass for two days. Efficacy, 
approximately 100 per cent. 

Santonin has for many years enjoyed the reputation of being the 
best ascaricide known, but critical tests show that in single therapeutic 
dose it is distinctly inferior to chenopodium for removing ascarids from 
dogs and swine. To develop its greatest efficacy it must be given 
in small doses repeated daily, and given in this way it appears to 
exert a cumulative action on the worms and is quite effective, a smaller 
total being more effective than a single dose larger than this total. 
Santonin and calomel, equal amounts, in doses of four to eight grains 
each, are commonly recommended for removing ascarids from swine, 
but chenopodium is better. 

Dosing swine is difficult. If capsules are used, care must be taken 
to avoid placing them in the retropharyngeal recess or the trachea, as 
in either place they will cause serious or fatal results. If the capsules 
are placed only on the back of the tongue, swine usually eject them 
from the mouth sooner or later. It is feasible to use a speculum and 
pass a stomach tube; a horse catheter may be used as such a tube. 
Swine are noisy, dirty, hard to catch and hold, and can bite viciously, 
and these things, as already noted, account in part for the demand for 
“something to put in the feed” to remove worms from swine. How¬ 
ever, experiments indicate that drugs placed in the feed are wasted for 
the most part, the anthelmintic efficacy falling off very seriously or 
being entirely lost. 

Carbon tetrachlorid does not appear to be a very satisfactory 
anthelmintic for use in removing worms from swine. It is fairly 
effective in removing ascarids when given at a dose rate of 0.6 cc. 
per kilo, but this dose is much more bulky than that of chenopodium 
and is less effective. Furthermore, carbon tetrachlorid has a much 
smaller margin of safety for swine than for carnivores and poultry. 

85 


Stomach worms (Arduenna strongylina, Physocephalus sexalatus 
and Hyostrongylus rubidus) : Oil of chenopodium as for ascarids. This 
drug mixed with castor oil and milk and given in feed removed about 
60 per cent of the Arduenna present in an experiment animal, judging 
the efficacy from the worms passed and those left postmortem; worms 
passed for four days. As noted in regard to stomach worms in horses 
and sheep, probably some worms were digested after being killed and 
the drug was probably distinctly more effective than the fecal findings 
indicate. With this evidence as to the efficacy of the drug when 
given in feed, it seems safe to assume that it will be more effective 
when properly administered. The stomach worms which are protected 
by burrowing in the mucosa or which are embedded in a thick mucous 
coating may be and probably are protected from the action of an¬ 
thelmintics. 

Nodular worms: No satisfactory treatment known. The cheno¬ 
podium treatment as given for ascarids will remove some nodular 
worms. 

Thorny-headed worms: No effective treatment known as yet. 
Turpentine and copper sulphate have each been recommended, but we 
lack experimental evidence in regard to these drugs. Oleoresin of 
male fern has been found effective in a case of human infestation with 
one. species of thorny-headed worms, not the species in swine, and 
would be worth trying against the swine parasites. 

Tapeworms: Many writers give treatments for tapeworms in 

swine. For practical purposes, swine are not infested with adult tape¬ 
worms. The; few reported cases of these worms in swine apparently 
deal. with, tapeworms of sheep or other animals, these tapeworms hav¬ 
ing been swallowed by swine in eating the intestines of the true host, 
or with tapeworms of animals other than swine which have undergone 
partial development in swine but have remained sterile in the unusual 
host. . 


TREATMENTS FOR DOG PARASITES 


Ascarids: Fast overnight. Oil of chenopodium, 0.1 cc. per kilo 
(1 cc. to a 22-pound dog), in capsule, immediately preceded or followed 
by 32 cc. (one fluid ounce) of castor oil. Purgation important. Febrile 
conditions, such as distemper, or mange are contraindications for 
treatment. Dog is usually salivated and may vomit, but drug is 
usually effective in spite of vomiting. Worms pass up to seven days, 
coming away after treatment as follows: First day, 82.7 per cent, 
second day, 7.7 per cent; third day, 4.3 per cent; fourth day, 3.1 per 
cent. These are the figures for a large series of dogs. Efficacy, ap¬ 
proximately 100 per cent. 

Another treatment: Fast overnight. Carbon tetrachlorid, 0.3 cc. 
per kilo (3 cc. for 22-pound dog) in hard capsules. Purgatives may 
be given 2 to 3 hours later. Care must be taken not to-get the drug 
into the lungs. Efficacy, 80 to 100 per cent. This drug is less 
effective for removing ascarids from dogs than is chenopodium, but 
it is also safer (therapeutic dose has an indicated safety factor of 53) 
and is preferable in the cases of patients that are very young, very 
old, feeble, or suffering from mange or febrile conditions. In general 
the drug can be given with safety to pups two weeks old. 

Another treatment: Where there is inflammation of the digest¬ 
ive tract, santonin may be the drug of choice as it is not a gastro¬ 
intestinal irritant. Carbon tetrachlorid would be the next choice 
under these conditions, chenopodium being distinctly irritant. San¬ 
tonin should be given in doses of 0.5 to 1 grain daily, with an equal 
amount of calomel, for several days. Give early in the morning 
and do not feed dog for two to three hours after treatment. 

Hookworms. The carbon tetrachlorid treatment as outlined for 
aficarids. Worms pass for four days. In a series of experiments with 


87 


various drugs, hookworms passed as follows: First day, 74.1 per 
cent; second day, 15.7 per cent; third day, 7.4 per cent; fourth day, 
2.8 per cent. Efficacy of carbon tetrachlorid, approximately 100 per 
cent. 

Whipworms. Santonin, 0.5 to 1 grain, with an equal amount of 
calomel daily, two to three hours before feeding in the morning, for 
one week. Suspend treatment for one week, and then repeat for a 
week. The results should be checked by examination of the feces 
for worms passed and for eggs persisting, to make sure of the re¬ 
sults, but this makes a fairly satisfactory routine treatment where 
such examinations cannot well be made. The difficulty in removing 

whipworms is due to the fact that drugs do not always enter the 

cecum after passing the ileo-colic valve. Even relatively feeble 
anthelmintics will remove whipworms when they enter the cecum. 
Entrance into the cecum can be ensured to some extent by using 

repeated doses or very large doses. For repeated doses a non-ir¬ 

ritant drug, such as santonin, is distinctly indicated. If large doses 
are to be employed, it is advisable to use a drug of low toxicity and 
a high safety factor, such as carbon tetrachlorid. Carbon tetrachlorid 
in one large dose, 1 cc. per kilo, will sometimes prove effective in re¬ 
moving whipworms. Strong animals will tolerate this dose or much 
larger doses, but it is inadvisable to use large doses of anthelmintics 
in the case of old, very young, or sick or weak animals. 

Tapeworms. Fast overnight. Arecoline hydrobromid by mouth, 
Vi grain to small dogs; grain to dogs of average size. No purga¬ 
tive; the drug itself is purgative. Worms usually pass in half an 
hour, but tapeworms of the genus Dipylidium may pass for four days 
after tapeworm treatments, the worms in a series of experiments 
coming away as follows: First day, 91 per cent; second day, 7.4 
per cent; third day, none; fourth day, 1.6 per cent. This tapeworm 


88 


treatment, developed by Lentz, has been highly recommended on the 
strength of clinical experience, but no critical tests have yet been 
published giving exact information in regard to its efficacy. No 
dosage for large dogs has yet been given, but it seems probable that 
the dose should be increased up to Yi grain for large dogs. 


A treatment developed by Dr. E. T. Davison is as follows: Fast 
overnight. At 10:00 A. M., for dogs of average size, give four 10- 
grain capsules (those holding 10 grains of quinine) filled with oleoresin 
of male fern, and follow with an ounce of water or milk, preferably 
milk. Forty-five minutes later give four 10-grain capsules full of 
freshly ground areca nut. It is essential that the areca nut be 
freshly ground; after grinding it gradually loses its potency and 

finally becomes inert. Follow the areca nut with an ounce of milk 
or water as above. Worms usually pass in a half hour to an hour. 
After dosing tie the dog’s head as high as it can be held without 
choking, to prevent vomiting. 

Oleoresin of male fern, 3.75 cc. (1 fluid dram) in capsules, fol¬ 
lowed immediately by 32 cc. (1 fluid ounce) of castor oil, is highly 

effective against tapeworms. The theory that castor oil increases 

the toxicity of male fern is not supported by experience and experi¬ 
ments; critical tests show that castor oil is protective to a consider¬ 
able extent against the toxic effects of male fern where the two drugs 
are given together. 

Kamala, 2 to 8 gms. (0.5 to 2 drams) in syrup, is very effective 
against tapeworms. 

Tapeworms of the genus Dipylidium, the double-pored tapeworms 
of carnivores, are difficult to remove entirely owing to the habit these 
worms have of sewing the head and the anterior portion of the strobila 
into the mucosa. Thus protected the worm may lose the posterior 
portion of the strobila from anthelmintic action, but the head will re- 


89 


main to renew the infestation. Treatments must be repeated as often 
as necessary. As fleas and lice are intermediate hosts, the removal of 
these worms should be accompanied by the eradication of the insect 
hosts or reinfestation usually follows in a short time. 

Flukes. According to Jeffreys, carbon tetrachlorid as given above 
for ascarids will remove the intestinal flukes from foxes, and it may 
prove equally effective in removing these flukes from dogs. 

TREATMENTS FOR CAT PARASITES. 

Ascarids. Fast overnight. Oil of chenopodium, 0.05 cc. per kilo, 
immediately preceded or followed by a half ounce to an ounce of 
castor oil. Chenopodium is twice as toxic for cats as for dogs and 
should be used in the diminished dose given here. The carbon tetra¬ 
chlorid treatment is safer. 

Carbon tetrachlorid, 0.3 cc. per kilo, to animals fasted overnight, 
as for dogs. Carbon tetrachlorid is twice as toxic for cats as for 
dogs, but the safety factor for the therapeutic dose is about 27, whereas 
that for chenopodium as given above is about five. As a rule, carbon 
tetrachlorid can be given with safety to kittens three weeks old. 

Hookworms. Carbon tetrachlorid as above. 

Tapeworms. The same drugs that are used to remove tape¬ 
worms from dogs may be used to remove tapeworms from cats, the 
dose being diminished in accordance with the size of the animal. 

TREATMENTS FOR FOX PARASITES 

Ascarids. Carbon tetrachlorid in capsules at the rate of 0.3 cc. 
per kilo, as for hookworms in dogs. It is reported that the use of 
a small balling gun and a speculum is the most satisfactory mode of 
administering these capsules to foxes. Allen recommends chenopodium, 
15 to 20 minims, in capsules, for adults; give adequate dose of castor oil 
with this. The efficacy of both drugs against ascarids in foxes is re¬ 
ported as approximately 100 per cent. 

90 


Hookworms. Carbon tetrachlorid as given above for ascarids. 
Efficacy, 93 per cent or higher. 

Whipworms. The treatment recommended in the case of the 
dog whipworm would probably be effective, using suitable doses, 
but unless treatment was very necessary the difficulties of giving 
repeated doses of santonin to foxes would not warrant it. 

Tapeworms. The treatments recommended in the case of dog 
tapeworms would probably be effective, using suitable doses. 

Flukes. Carbon tetrachlorid, as given above for ascarids, is re¬ 
ported by Jeffreys as 100 per cent effective in removing intestinal 
flukes from foxes. 

TREATMENTS FOR POULTRY PARASITES. 

Large roundworms (Ascaridia perspicillum) : A mass treatment 
recommended by Herms and Beach is as follows: For 100 birds, steep 
one pound of finely chopped tobacco stems for two hours in water 
enough to cover them. Mix the stems and the liquid with one-half 
the usual ration of ground feed. The day previous to treatment with¬ 
hold all feed, giving water only. After fasting 24 hours, feed the 
mash thus prepared, and two hours after it is cleaned up give one- 
fourth of the usual amount of ground feed mixed with water in 
which Epsom salt has been dissolved at the rate of 11 ounces for 
each 100 birds. The treatment should be repeated 10 days later. 

For a mass treatment where only a single treatment is given, use 
one teaspoonful (approximately one fluid dram or 3.75 cc.) of oil of 
chenopodium, thoroughly mixed with a moist mash, for each 12 birds. 

For individual treatments, oil of chenopodium, 0.2 cc., in castor oil, 
2 cc., has been found to remove 69 per cent of these worms;, turpen¬ 
tine, 2 cc., in castor oil, 8 cc., has been found to remove 76 per cent 
of these worms. 

Cecum worm (Heterakis papillosa) : Rectal injections of oil of 
chenopodium, 0.1 cc., in a bland oil (as cottonseed oil), 5 cc., to birds 

91 


weighing 1.5 pounds (ca. 700 grams), given by means of a hard rub¬ 
ber rectal syringe, infant’s size, has been found to remove 90 per 
cent of these worms. Double the dose for birds weighing three 
pounds or over. The tip of the syringe should be passed along the 
floor of the cloaca. 

For a mass treatment, the tobacco treatment given above for the 
large roundworm has been found, when given once and not repeated, 
to remove about one-fifth of these cecum worms. If repeated at in¬ 
tervals of a month this might serve as a control measure of some 
value. 

Spirurids. We have as yet no known effective treatment for the 
spirurid worms which occur more or less embedded in the tissues of 
the digestive tract of poultry. 

Tapeworms. No satisfactory treatment has yet been established 
for tapeworms in poultry. A mass treatment which has been recom¬ 
mended is as follows: A gallon of a mixture of wheat and oats, to 
which is added a small tablespoonful of concentrated lye, is cooked 
slowly for about two hours and allowed to cool. The birds are fasted 
for 15 hours and then given as much of the mixture as they will eat, 
with plenty of water. 


ADDENDUM 

Lamson has recently reported good results in removing stomach 
worms from sheep by means of a nicotine sulphate solution. Using a 
commercial preparation containing 40 per cent of this substance, he 
makes solutions of three strengths, adding one, two or three teaspoon- 
fuls to a quart of water. For weak sheep, use the weakest solution at 
the rate of 4 ounces to an adult and 2 ounces to a lamb. For average 
animals use the same doses of the stronger solution, and for strong 
animals the same does of the strongest solution. Fast for 12 hours 
before and 8 hours after treatment. 


92 


The Methods and Technic of 
Administering Anthelmintics 

T HE method of administering drugs is a matter of considerable 
practical importance. Much of the veterinarian’s success depends 
on the ease with which he can administer a drug, and there is 
often a marked difference between the young inexperienced man and 
the older experienced man in the readiness with which they solve the 
problems of treatment presented by refractory patients. The inept 
manner of the beginner creates an unfavorable impression on the client 
and contrasts unfavorably with the skill of the practiced man accus¬ 
tomed to handling animals. Familiarity with animals and with 
methods of handling them is, like many other things, best acquired in 
childhood, and the boy who is raised with horses, cattle, sheep, swine, 
dogs, cats and poultry becomes the man who finds the administration 
of drugs an easy matter, as a rule. Owing to the nature of the drugs 
used in anthelmintic medication, the common necessity for fasting in 
connection with the treatment, and for other reasons, resort to the 
administration of drugs by the hypodermic needle or in feed, and 
similar easy methods of administering treatment are not feasible or 
are usually not feasible. This subject appears, therefore, to warrant 
some special consideration. It is discussed here with reference to the 
animals to be treated. 


HORSE 

It is not an uncommon practice to administer anthelmintics in 
feed to horses. However, the results obtained with drugs which are 
commonly administered in this way are not very satisfactory. Hall, 
Wilson and Wigdor reported a series of critical tests on horses with 
various anthelmintics, including, among other things, tests of tartar 
emetic and of iron sulphate administered in the feed. These drugs 
are often recommended for administration in this manner. 

One horse was given 2 drams of iron sulphate in a mash daily for 7 
days; it passed 4 cylicostomes, postmortem it had 288 cylicostomes, 80 
strongyles and 3 pinworms. Another horse was given 14 doses of 
iron sulphate, in amounts of 4 drams to a dose, in a medicated mash 


93 


over a period of 12 days; it passed 3 cylicostomes; it was then put on 
a chenopodium treatment which removed all the cylicostomes (1242), 
95 per cent of the Strongylus (78 out of 82) and 25 per cent of the 
ascarids (1 out of 4). (The papers in question do not clearly bring 
out the fact that the ascarid passed after chenopodium and not after 
iron sulphate.) Another horse was given 2 drams of tartar emetic in 
a mash daily for 5 days; it passed 10 cylicostomes, 1 Strongylus, 1 
pinworm, and 1 ascarid; postmortem it had 5474 cylicostomes, 312 
Strongylus and 11 ascarids; the small intestine showed numerous 
petechiae and ecchymoses which were apparently due to the drug. 

These experiments indicate clearly that iron sulphate or tartar 
emetic given in a mash for several days in the amounts stated are 
quite ineffective against cylicostomes, Strongylus and ascarids. Iron 
sulphate is also ineffective against pinworms and the efficacy shown 
by tartar emetic against pinworms does not' warrant its use in view 
of the lesions caused by this drug and the greater efficacy shown 
against cylicostomes and Strongylus by chonopodium, which is equally 
effective against pinworms and is therefore the drug of choice for re¬ 
moving worms from the large intestine of the horse. 

CARBON BISULPHID AND CHENOPODIUM 

The two drugs which are most effective in removing worms and 
other parasites from the digestive tract of the horse are carbon bi- 
sulphid, which will remove all or practically all of the ascarids and 
bots, and chenopodium, which will remove all or practically all of the 
cylicostomes, Strongylus and pinworms from the large intestine. These 
drugs should be administered in capsules. It is hardly necessary to tell 
veterinarians how to administer capsules to horses. Some prefer the 
balling gun, which is a very satisfactory instrument if properly used 
and which affords safety to the operator from injury to the hands. 
Others prefer to give a capsule by hand, and veterinarians in general 
are familiar with the necessity for holding the hand with the thumb up 
instead of with the palm down in order to avoid injury from the 
animal’s teeth. Skill with the balling gun or hand is largely a matter 
of practice, and either method is satisfactory with a skilled operator. 

PURGATION AFTER ADMINISTRATION 

No purgation is necessary or advisable after carbon bisulphid, but 
it is advisable and desirable after chenopodium. Hall, Wilson and 
Wigdor used a quart of castor oil b}' drench after chenopodium. 
Drenching is regarded as rather risky business, but the safety factor in 


94 


drenching is largely dependent on the time element. Haste is in¬ 
advisable, and if drenching is done leisurely, it is usually a compara¬ 
tively safe procedure. Wright prefers an aloes ball to linseed oil; 
this ball may be given with the balling gun or by hand. 


The use of the stomach tube is one solution of the drenching prob¬ 
lem, and appears to be especially indicated in infestation with stomach 
worms, Habronema spp., the worms being removed by anthelmintic 
lavage. i',! 


CATTLE 

In the writer’s limited experience in administering anthelmintics 
to cattle it is not particularly difficult to give anthelmintics to them 
by stomach tube or by drench, or in capsules by means of the balling 
gun, but the few experiments along this line have not suggested any 
niceties of technic that deserve mention. 


SHEEP 

Experience shows that it is a simple matter to drench sheep with 
most anthelmintics, such as the copper sulphate solution, and with 
suitable apparatus these animals may be thus treated at the rate of 50 
to 100 an hour. 

DRENCH CAREFULLY, PREFERABLY WITH TUBE 

Too much haste is, of course, inadvisable in drenching sheep as in 
drenching horses. If such volatile drugs as gasoline are used the 
danger is much greater, as sheep fight against drenching with gaso¬ 
line and this often results in the gasoline getting into the lungs with 
serious results. In drenching a metal tube is usually inserted in the 
mouth, this tube being either end portion of a funnel, rubber tube 
and metal tube arrangement, or a dose syringe, or some similar ar¬ 
rangement for drenching. A hard rubber tube is unsatisfactory as 
sheep or cattle have little difficulty in breaking hard rubber by chew¬ 
ing on it. It is advisable to move the metal tube about in the mouth 
as this seems to facilitate or stimulate swallowing on the part of the 
animal being treated. The ease with which sheep may be drenched 
seems to render the use of a stomach tube unnecessary for dosing ex¬ 
cept in the case of volatile drugs. 

GIVE CAPSULES WITH BALLING GUN 

The administration of capsules to sheep appears to be a simple 
matter if a balling gun is used. The mouth of a sheep is too small 
to permit of the technic that is used in balling a horse by hand and 

95 


the structure of the molars and shape and size of the mouth is such 
that the technic used in giving a capsule to a dog by hand is un¬ 
satisfactory and will usually result in injury to the hand. 


SWINE 

The administration of anthelmintics to swine is a difficult matter. 
These animals are hard to restrain, annoyingly noisy, and have a 
powerful bite. 

HOLD MOUTH OPEN BY LOOPING EACH JAW 

In drenching them it is a common pratice to hold the mouth open 
by means of two loops, one about the lower jaw and one about the 
upper jaw. The loops are made of various things, but the use of wire 
seems inadvisable and cruel as it commonly results in injury to the 
gums or teeth. Even small rope has the same objection and it seems 
advisable to use rather large rope or loops of rubber hose. A specu¬ 
lum of some type is often used. Metal tubes used in drenching swine 
must be strong, as swine will crush small metal tubes between the 
teeth. The apparatus used by Young is shown here in Figure 2 and 
his method of using it in Figure 3. Johl uses a cylindrical speculum 
in the form of a curved metal tube in passing the stomach tube on 
swine. According to Dr. E. R. Steel it is possible to administer the 
mixture of chenopodium and castor oil by stomach tube to 80 pigs an 
hour. 

OTHER METHODS 

Numerous drenching methods have been advocated and used, in¬ 
cluding the use of a rubber hose which the animal is allowed to chew 
as the drench is poured down it, or the use of an old boot from which 
the toe has been cut, the toe part being put in the mouth for the ani¬ 
mal to chew while the drenching is poured in the upper portion of the 
boot. 


BALLING HOGS 

Capsules should be given to swine by means of a balling gun, as 
the bite of these animals is too severe to permit of risking the hand. 
In using the balling gun it is customary to hold the mouth open by 
means of loops or a speculum. The danger incident to administering 
capsules to swine has been pointed out frequently of late years and 
most veterinarians are familiar with the fact that a capsule must not 


96 



be placed high enough to enter the retropharyngeal recess or low 
enough to enter the larynx (Fig. 80), and that failure to insert the 
capsule well back frequently results in the animal spitting out the 
capsule at the first opportunity after it is released. 



Fig. 80. Vertical section through the median longitudinal line of a swine’s head, 
showing the median pharyngeal recess, a pocket about 1.5 inches long. From Hall, 
1920, after Sisson. 

FEED MECHANICALLY PROTECTS WORMS 

As a result of the difficultaies in drenching swine or giving them 
capsules, there is a persistent demand for an anthelmintic that can be 
given to swine in feed with satisfactory results. Such a procedure 
may be developed or may exist at present, but the writer is not familiar 
with anything of the sort and all our experience up to the present in¬ 
dicates that the feed dilutes and mechanically protects the worms, 
and that the amounts ingested vary too greatly with different animals 
to ensure either safety on one hand or efficacy on the other. How¬ 
ever, it may prove advantageous to give saline purgatives to swine in 
a light soft feed two or three hours after anthelmintic treatment, and 
this method of obtaining purgation is being used by some veterinarians. 



Fig 2 Speculum and syringes with attached tubes for dosing swine by stomach tube. 

From Young, 1923. 

97 







Fig. 3. Administering an anthelmintic to a pig by means of the stomach tube 

From Young, 1923. 


THE STOMACH TUBE SEEMS SATISFACTORY 

One solution of the problem of administering anthelmintics to 
swine is the use of the stomach tube, and some practising veterinarians 
state that this is a feasible and satisfactory method of treating them. 
The writer finds that this method seems quite satisfactory and not un¬ 
duly wasteful of time if one considers the danger in the use of capsules 
and the waste of time and drugs and the uncertainty as to dose ad¬ 
ministered in drenching. A tube the size of a horse catheter may be 
used for animals of moderate and large size, the mouth being held 
open with a speculum or with loops. 


%. 

, DOGS 

The administration of drenches to dogs seems to present little 
difficulty as a rule, but many veterinarians have difficulty in administer¬ 
ing capsules to dogs. The writer’s familiarity with dogs as a boy who 
always owned a dog and his subsequent experience in the treatment 
of hundreds of experiment dogs has led him to formulate certain 
opinions in regard to the method of giving capsules to these animals. 


98 











BALLING GUN METHOD FEASIBLE. 

It is quite feasible to give capsules to the dog by means of a 
balling gun, but out of hundreds of dogs treated, these dogs being un¬ 
selected animals obtained from various dog pounds, it is necessary to 
resort to the balling gun in the case of less than one animal in a 
hundred. 


MORE TRACTABLE AWAY FROM HOME 

One aid to dosing in the case of a dog is to get the animal off 
his home grounds and in an unusual and unfamiliar environment. The 
dog in his own home may regard the veterinarian as an intruder and 
trespasser; in the veterinarian’s office or hospital the dog seems to 
commonly regard himself as the intruder and trespasser. For most 
dogs, though not all, it is an advantage to have them at your office 
or hospital. An additional advantage may be gained by putting the 
dog on a table to treat it. The dog is accustomed to life at a plane 
somewhere near the level of a person’s knees and is not at ease when 
elevated to a position near the level of the human chest or head. 
Such a position places him at a disadvantage and he is usually willing 
to submit to anything you propose. 


DOG KNOWS THE TIMOROUS 

To get the best results one must not be afraid of dogs or an oc¬ 
casional bite. In your own mind you should feel that the procedure 
of treatment is a commonplace matter to which no dog can take ex¬ 
ception and to which your patient is not going to take exception. If 
you have this mental attitude, the dog will accept it as correct more 
than ninety-nine time out of a hundred. If you are afraid of the dog 
or doubtful of what you are going to do, the dog will usually realize 
this and instead of being unafraid or only mildly apprehensive of 
your proceedings, he will be frightened and may take measures ac¬ 
cordingly. 


METHOD OF GIVING CAPSULES 

The writer’s method of giving capsules is as follows: The cap¬ 
sules are prepared and placed on a table or in a shallow bowl on the 
table. The dog is put on the table and held by the upper jaw with 
the left hand if no resistance is available for restraint. Assistance is 


99 


usually unnecessary anyway. A capsule is picked up between the 
index and middle fingers and these two fingers are pushed along the 
top of the mouth and well down the throat, the thumb being outside 
of the mouth on one side and the ring finger and little finger outside 
of the other side of the mouth. As soon as the capsule is well down 
the throat, the middle finger is slipped behind the capsule and the 
capsule pushed as far as it will go, a procedure which ensures that 
the capsule will be swallowed. If additional capsules are to be given, 
the hand is wiped on a towel to rid it of saliva which would make a 
capsule slippery and give an insecure grip on it. The entire procedure 
is governed by the sense of touch and can be carried out with the 
eyes shut as well as with the eyes open—perhaps better. In the case 
of those dogs which have a short stop, such as Boston bull terriers, the 
soft palate will often present an obstacle, the tips of the fingers catch¬ 
ing in it, and it is necessary to carefully slip the fingers under this. 


BITING DOGS DIFFER FROM FOXES 

The outstanding objection to this method of treatment is that the 
dog may bite. In this connection certain things appear to be true. 
For one thing, a dog, contrary to what is said to be true of a fox, 
will almost never bite a hand that is inserted in his mouth. It is 
necessary to use a balling gun in giving capsules to foxes after they 
are .6 weeks old, as an older fox will seize and hold a hand if it is 
placed in the fox s mouth. A dog wants to do his own biting, mak¬ 
ing the preliminary attack by seizing the hand. If a hand is pushed 
in his mouth, a dog’s first instinct is to get rid of it. Even with 
vicious dogs, if the hand is slipped around the side of the head and 
shoved boldly into the mouth, the dog does not bite it, but attempts 
to get away from it or get it out. 


SCRATCHES FROM SHARP TEETH A DANGER 

Injury to the hand is usually confined to scratches from small 
dogs having fine, needle-like teeth. There is also the danger from 
rabies. This is a real danger. If the veterinarian regards it as present 
in any or all cases it is sufficient reason for using the balling gun. 
However, there are always risks in veterinary practice and we come to 
take some of them as a matter of course. 

There should be no danger of getting capsules in the trachea when 

100 


they are given with the fingers; there is danger of this in using the 
balling gun and some foxes are killed in this way. 

THE STOMACH TUBE HAS ADVANTAGES 

It is an easy matter to pass a stomach tube in the dog. A form 
of speculum which is commonly used consists of a piece of wood of 
a size suitable for the size of the dog to be treated, with a hole large 
enough to permit the passage of the tube bored through the middle 
of the piece, and with the ends of the piece rounded to make a grip 
for the hands on each side of the mouth. More elaborate metal 
speculums of various types may be purchased from commercial houses. 
One advantage of the stomach tube in dosing dogs is that the animal 
does not taste the drug and is less disposed to vomit after the ad¬ 
ministration of some unpalatable substances. 


POULTRY 
Mass Treatment 

The relatively small value of individual birds and the large number 
commonly present has given the subject of mass treatments, as 
opposed to individual treatments with anthelmintics, & greater amount 
of interest and attention in connection with treatments for poultry than 
in connection with treatments for other kinds of animals. As a result 
there have been developed such methods as the use of a tobacco infus¬ 
ion in the feed for the removal of roundworms from the small intestine, 
and the subsequent modification of this method in the use of tobacco 
dust in the feed for a considerable period of time. In the same way, 
a small amount of lye added to a cooked mixture of wheat and oats 
has been proposed for the treatment of tapeworm infestations in 
poultry. 


INDIVIDUAL TREATMENTS 

For individual treatments, birds may be drenched by means of a 
medicine dropper or drugs may be given by means of a stomach tube, 
a small human catheter serving as a tube. Dr. Bernard Gallagher 
tells me that a glass funnel or a pipette, with or without a rubber 
bulb, may be used to give drugs to fowls, the stem of the funnel or 
the pipette being passed to the crop or part way down the esophagus. 


101 



Capsules may be given with the aid of a pair of round-tipped, 
blunt dissecting forceps. According to Dr. Gallagher, quite large cap¬ 
sules may be given to birds, but it is necessary to push these down 
the esophagus, preferably by means of a rubber tube. He also ad¬ 
ministers some drugs by means of an injection directly to the crop 
through the skin, using a hypodermic syringe, a method which has 
been reported by Ward and Gallagher in connection with the admin¬ 
istration of turpentine as an anthelmintic. Rectal injections are easily 
administered by means of an infant’s-size hard rubber syringe, the 
tip of the syringe being passed along the floor of the cloaca. The 
oviduct opens on the side of the cloaca and there is practically no 
danger of entering it. Rectal injections have been found effective in 
removing cecum worms. 


* 


102 


















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